Question: What is the location of the four observation towers belonging to the weapons range near RAF Wainfleet?

Context articles: Bismarck tower
List of tallest buildings in Estonia
44th New York Monument
List of tallest buildings in the European Union
Bootmakers' Tower
Tower Hotel (Niagara Falls)
Blue Mound State Park
RAF Wainfleet
RAF Tain
RAF Holbeach

A Bismarck tower (German: "Bismarckturm" ) is a specific type of monument built according to a more or less standard model across the Germany to honour its first chancellor, Otto von Bismarck (d. 1898).
 A total of 234 of these towers were inventoried by Kloss and Seele in 2007 but more have been discovered since making the total around 240.
 These towers were built between 1869 and 1934 and some 173 remain today.
 Quite a few of these towers, including all 47 based on Wilhelm Kreis's "Götterdämmerung" design, were built as so-called Bismarck Columns ("Bismarcksäulen") or were converted into them.
 This description goes back to the Student Union's competition held in 1899, which was to encourage the erection of as many beacons as possible (and not observation towers).
 But other Bismarck towers, e. g. those which were purely beacons with no observation function, were often called Bismarck columns.
This is a list of tallest buildings in Estonia.
 All buildings over 50 m are listed.
 Only habitable building are ranked, which excludes radio masts and towers, observation towers, steeples, chimneys and other tall architectural structures.
 For those, see List of tallest structures in Estonia.
The 44th and 12th New York Infantry Monument ( ) is a Gettysburg Battlefield memorial erected near the summit of Little Round Top to commemorate combat in the Battle of Little Round Top.
 The castellated building is the largest monument to a regiment on the battlefield, is the 1st of only 2 Battle of Gettysburg memorials with observation decks (cf. 1910 The Pennsylvania State Memorial), and supplemented the Gettysburg Battlefield Memorial Association wooden towers on Big Round Top and East Cemetery Hill (replaced in 1895 with 2 observation towers at Big Round Top and at Culp's Hill).
 The July 3, 1893, memorial dedication was the site of an altercation against photographer William H. Tipton by Gen. Sickles, who was served a court writ the following day and was forced out of the New York Monuments Commission in 1912 after malfeasance.
This list ranks the tallest buildings in the European Union that stand at least 140 m tall, based on standard height measurement.
 This means that spires and other architectural details are included in the official height, but not antenna masts, as it is defined by the Council on Tall Buildings and Urban Habitat.
 Only habitable buildings are ranked, which excludes radio masts and towers, observation towers, cathedrals, steeples, chimneys and other tall architectural structures.
 Since 2011, the tallest building in the EU has been The Shard in London, United Kingdom, at 310 m .
The Bootmakers' Tower (Turnul Cizmarilor in Romanian) is located in the north-east of the Citadel in Sighişoara,belonging to Mureș County in Romania.
 The building has baroque architectural influences.
 Despite its low height, the tower is interesting due to its hexagonal plan, an outer diameter of 10 meters long and a roof hosting two small and elegant observation towers, one facing South-east and one North-west.
 The current tower was built in 1681 on the site of a previous destroyed tower.
The Tower Hotel, opened in 1962, is located in the Fallsview district of Niagara Falls, Ontario and was the first of the modern observation towers built near the brink of the Falls.
 It features an indoor observation deck, restaurant, wedding chapel, and hotel.
 From street level, the tower is 99 metres (325 feet) tall, however it is situated 160 metres (525 feet) above the falls.
 The tower assumed its present name in 2010 as a result of its most recent renovation, however as Minolta was the longest-tenured sponsor of the building it is frequently still known as the Minolta Tower among tourists and locals.
Blue Mound State Park is a state park of Wisconsin, USA, located atop the largest hill in the southern half of the state, near the village of Blue Mounds.
 The 1153 acre park features a pair of observation towers affording views of the Wisconsin River valley and Baraboo Range to the north, the mounds, buttes, and rolling forests of the Driftless Area to the south and west, and the young glacial plains and city of Madison to the east.
RAF Wainfleet was a Royal Air Force weapons range on The Wash on the east coast of England near Wainfleet, in the civil parish of Friskney, although the north-east part of the range was in Wainfleet St Mary.
 Other ranges nearby include RAF Holbeach, also on The Wash, and Donna Nook.
 It was also known as The Wash (North side) Bombing Range.
 It was only a few miles south-west of Gibraltar Point.
RAF Tain is a Ministry of Defence air weapons range on the Moray Firth near Tain in Scotland.
 Royal Air Force aircrews from RAF Lossiemouth are trained in air weaponry on the range, along with NATO aircrew.
RAF Holbeach, now DIO Holbeach AWR is a Royal Air Force academic air weapons range (AWR) situated between Boston and King's Lynn near Gedney Drove End on The Wash, in Lincolnshire, eastern England.
 Most of the range, including the control tower and four observation towers (Quads) are in Gedney, but it does overlap with Holbeach to the west.
 On UK Civil Aviation Authority issued aeronautical charts the military Danger Area is found marked and identified by the code WRDA D207/II or the ICAO code EG D207 (Weapons Range Danger Area or United Kingdom Danger, 207, the danger altitude is usually up to twenty-three thousand feet AMSL).