Eski Mosque or Old Mosque (Turkish: "Eski Camii" , meaning "Old Mosque"), can refer to a number of mosques across the former Ottoman Empire:
Tashkyopryu Mosque (Bulgarian: Ташкьопрю джамия "Tashkyopryu Dzhamiya", Turkish: "Taşköprü Camii") is a mosque in Plovdiv, Bulgaria , built by Ottoman Turks in 16th century during their 500-year rule in today's Bulgaria.
 It is currently the third mosque in Plovdiv which is in good condition after Dzhumaya Mosque and Imaret Mosque.
 It is currently inactive despite efforts and demands, mainly by Turks of Bulgaria, to give active status for it.
The Eski Mosque (Macedonian: Татар Синан Бег Џамија ; ; Turkish: "Eski Camii" ; "Old mosque") was built in 1532 and reconstructed 1751 and 2008 in the city of Kumanovo, Macedonia, at a time when the Republic of Macedonia was a part of the Ottoman Empire.
 In recent years there has been reconstruction work inside and outside the mosque.
Al-Asha'ir Mosque or the Great Mosque of Zabid (Arabic: جامع الأشاعرة‎ ‎ ), is an ancient mosque in the historic city of Zabid, Yemen.
 It is located near the Zubaid market, forming a part of UNESCO World Heritage Site Historic Town of Zabid.
 Its foundation is owing to the great Sahabi Abu Musa al-Ash'ari in the year 8 AH or 629 CE and since then the mosque was the first mosque to achieve its spiritual and historical status in Yemen.
 Local tradition narrates that the mosque is fifth oldest mosque in the history of Islam, making it one of the oldest mosques in the world.
 The mosque underwent several renovations, but the most important additions of which were made during the reign of Sultan Al-Mansour Abdul Wahab bin Dawood in the year 1486, and since then the shape of the mosque remained as it is to this day, as pointed out by the great historian Ibn al-Dhibir in his book "In Order to Benefit".
Nusretiye Mosque is an ornate mosque located in Tophane district of Beyoğlu, Istanbul, Turkey.
 While its architecture is influenced by Islamic elements, it retains a Baroque style, making it unique to the city.
 It was built in 1823-1826 by Sultan Mahmut II.
Nusretiye Clock Tower, aka Tophane Clock Tower, is a clock tower situated in Tophane, a neighborhood in Beyoğlu district of Istanbul, Turkey next to Nusretiye Mosque and Tophane Kiosk at the European waterfront of Bosphorus.
 It was ordered by the Ottoman sultan Abdülmecid I (1823-1861), designed by architect Garabet Amira Balyan and completed in 1848.
Istiqlal Mosque, or Masjid Istiqlal, (Independence Mosque) in Otoka, Sarajevo, Bosnia and Herzegovina is one of the largest mosques in the city.
 It was named after Istiqlal Mosque, Jakarta, the national mosque of Indonesia, since the mosque was the gift from Indonesian people and government for Bosnia and Herzegovina as a token of solidarity and friendship between two nations.
 The name ""istiqlal"" is Arabic word for "independence", thus it is also meant to commemorate the independence of Bosnia and Herzegovina.
 It is also colloquially known as "Indonesian mosque" or "Suharto mosque", as the credit to the initiator of the mosque construction.
Eski Imaret Mosque (Turkish: "Eski Imaret Camii" ) is a former Eastern Orthodox church converted into a mosque by the Ottomans.
 The church has traditionally been identified with that belonging to the Monastery of Christ Pantepoptes (Greek: Μονή του Χριστού Παντεπόπτη ), meaning "Christ the all-seeing".
 It is the only documented 11th-century church in Istanbul which survives intact, and represents a key monument of middle Byzantine architecture.
 Despite that, the building remains one among the least studied of the city.
Al-Osmani Mosque is a mosque in Medan, North Sumatra.
 The mosque is also known as Labuhan mosque because of its location in the district of Medan Labuhan.
 The mosque is located on the K.L. Yos Sudarso road, subdistrict of Pekan Labuhan, about 20 kilometers north of the city of Medan.
 In front of this mosque there are a school, named YASPI School (Islamic Education Foundation) and not far from the mosque there are a Chinese temple named "Pekong Lima" and in front of the temple there is a path that leads to Labuhan market.
 The mosque is the oldest in the city of Medan.
Alaca Imaret Mosque or Ishak Pasha Mosque is a 15th-century Ottoman Mosque in Thessaloniki, Greece.

Question: Nusretiye Mosque and Eski Imaret Mosque are both in which city?
Answer: Istanbul, Turkey