Question: A sacred grove or sacred woods are any grove of trees that are of special religious importance to a particular culture, during the Northern Crusades, were religious wars undertaken by Catholic Christian military orders and kingdoms, there was a common practice of building churches on the sites of what?
Context: A sacred grove or sacred woods is any grove of trees of special religious importance to a particular culture.  For particular sacred groves, and other meanings, see: The Temple of Juno Lucina (Latin: "Aedes Iunonis Lucinae") was a temple dedicated to Juno Lucina (goddess of women in childbirth) on the Esquiline Hill in Rome.  It was dedicated on 1 March 375 BC, the festival of the Matronalia.  Before its construction, the cult of Juno Lucina occurred in a sacred grove or "lucus" (possibly the origin of the epithet Lucina) on the site - Varro dates the cult's origin to Titus Tatius, king of the Sabines.  It was struck by lightning in 190 BC, damaging the tympanum and doorway.  In 41 BC the quaestor Quintus Pedius built or rebuilt a wall possibly dating back to the sacred grove.  It was still operational in the imperial period, as attested to in inscriptions. The Altis (Greek: Ἄλτις) also referred to as the sanctuary to the gods, is the name of a location most well known for being a place of significant religious importance to the Ancient Greeks, considered to be a sacred precinct that was constructed and used from around 776 BCE to fourth century BCE and used for the worship of several Greek gods and goddesses.  Though the architects are not definitively known, it is generally attributed to be partially the work of Libon of Elis.  Located in the wide valley of the Alfeiós River (also Romanized as Alpheus, Alpheios) in the western part of Peloponnesus, around 18 kilometers away from the Ionian Sea, the name Altis was derived from a corruption of the Elean word alsos meaning “the grove” because the area was thickly wooded with oaks, plane trees, poplars, and olives.  The structure itself was an irregular quadrangular area more than 200 yards (183 meters) on each side and walled except to the North where it was bounded by the Kronion (Mount Kronos).  Inside were sanctuaries, the centers of religious worship, where the Greeks built over 70 temples, treasuries, altars, statues, and other structures in dedication to their gods.  The site was continuously inhabited from Mycenaean times until the 6th century BCE, where cult activity apparently first began at the foot of the hill of Kronos where altars to the goddesses Rhea, Gaia, and Eileithyia have left their traces.  Some other cults found here were devoted to figures like the hero cult of Pelops and Hippodameia (arguably the oldest shrine there) important mythological figures that are generally known for the founding myth of the Olympic Games.  During the time of the Dorian Invasion settlers from northwestern Greece inhabited the Altis whereby they introduced the worship of two major Greek deities in the Greek pantheon Hera and Zeus as well as constructing the most memorable things there, the Sanctuary and altar of Zeus, where to this day the ruins of the two principal temples: the Temple of Hera (6th century BCE) and the Temple of Zeus (5th century BCE) still remain.  Throughout Antiquity this Temple was considered the most perfect example of the Doric order.  This sanctuary also contained one of the highest concentrations of masterpieces of the ancient Mediterranean world though many have since been lost.  In connection with the cult of Zeus the Altis was then given the name Olympia, with famous Olympia, Greece being built on this site where also the first Olympic Games took place here, once every four years. Philautus sanctisilvaticus, also known as the sacred grove bushfrog or sacred grove bush frog, is a critically endangered species of frog in the Rhacophoridae family.  It is endemic to India and only known from its type locality at the Kapildhara Falls near Amarkantak, in the Madhya Pradesh state.  Its natural habitat is old growth tropical moist, semi-evergreen and mesic forest.  It is threatened by habitat loss caused by harvesting of wood for subsistence purposes, infrastructure development for tourism, and fires. A sacred grove or sacred woods are any grove of trees that are of special religious importance to a particular culture.  Sacred groves feature in various cultures throughout the world.  They were important features of the mythological landscape and cult practice of Celtic, Baltic, Germanic, ancient Greek, Near Eastern, Roman, and Slavic polytheism, and were also used in India, Japan, and West Africa.  Examples of sacred groves include the Greco-Roman "temenos", the Norse "hörgr", and the Celtic "nemeton", which was largely but not exclusively associated with Druidic practice.  During the Northern Crusades, there was a common practice of building churches on the sites of sacred groves.  The Lakota and various other North American tribes consider particular forests or other natural landmarks to be sacred. Religious texts (also known as scripture, or scriptures, from the Latin scriptura, meaning "a writing") are texts which religious traditions consider to be central to their religious practice or set of beliefs.  Religious texts may be used to provide meaning and purpose, evoke a deeper connection with the divine, convey religious truths, promote religious experience, foster communal identity, and guide individual and communal religious practice.  Religious texts often communicate the practices or values of a religious traditions and can be looked to as a set of guiding principles which dictate physical, mental, spiritual, or historical elements considered important to a specific religion.  The terms 'sacred' text and 'religious' text are not necessarily interchangeable in that some religious texts are believed to be sacred because of their nature as divinely or supernaturally revealed or inspired, whereas some religious texts are simply narratives pertaining to the general themes, practices, or important figures of the specific religion, and not necessarily considered sacred. The State of the Teutonic Order (German: "Staat des Deutschen Ordens" ; Latin: "Civitas Ordinis Theutonici" ), also called Deutschordensstaat (] ) or Ordensstaat (] ) in German, was a crusader state formed by the Teutonic Knights or Teutonic Order during the 13th century Northern Crusades along the Baltic Sea.  The state was based in Prussia after the Order's conquest of the Pagan Old Prussians which began in 1230.  It expanded to include at various times Courland, Gotland, Livonia, Neumark, Pomerelia and Samogitia.  Its territory was in the modern countries of Estonia, Latvia, Lithuania, Poland, and Russia.  Most of the territory was conquered by military orders, after which German colonization occurred to varying effect. The Northern Crusades or Baltic Crusades were religious wars undertaken by Catholic Christian military orders and kingdoms, primarily against the pagan Baltic, Finnic and Western Slavic peoples around the southern and eastern shores of the Baltic Sea, and to a lesser extent also against Orthodox Christian Slavs (East Slavs).  The crusades took place mostly in the 12th and 13th centuries and resulted in the subjugation and forced baptism of indigenous peoples. Athenian sacred ships were ancient Athenian ships, often triremes, which had special religious functions such as serving in sacred processions ("theoria") or embassies or racing in boat races during religious festivals.  The two most famous such ships were the "Paralus" and the "Salaminia", which also served as the messenger ships of the Athenian government in the 5th and 4th centuries BC.  Other notable ships included one possibly named the "Delias", a "triakonter" (thirty-oared galley) believed to be the ship in which Theseus had sailed to Crete, and which was involved in several traditional theoria to Delos; the vessel was constantly repaired by replacing individual planks to keep it seaworthy while maintaining its identity as the same ship.  (For the philosophical question of the ship's identity, see Ship of Theseus.)  After the reforms of Cleisthenes, a ship was named for each of the ten tribes that political leader had created; these ships may also have been sacred ships. The Crusades were a series of religious wars sanctioned by the Latin Church in the medieval period.  The most commonly known Crusades are the campaigns in the Eastern Mediterranean aimed at recovering the Holy Land from Islamic rule but the term "Crusades" is also applied to other church-sanctioned campaigns.  These were fought for a variety of reasons including the suppression of paganism and heresy, the resolution of conflict among rival Roman Catholic groups, or for political and territorial advantage.  At the time of the early Crusades the word did not exist, only becoming the leading descriptive term around 1760.
Answer: sacred groves