At 57-hectares and with a range of natural and green habitats, Kranji Marshes is Singapore's largest freshwater farmland. The nature reserve is home to 170 species of birds, 54 types of butterflies, and 33 different kinds of dragonflies. The 10.65-metre-tall Raptor Tower offers a panoramic view of the surrounding marshes. Educational boards are placed around the open-air observatory deck of the tower, helping the eagle-eyed identify birds and pick out landmarks such as the Moorhen Pond and the BBC Shortwave relay station in the distance.