Up on Calton Hill sits this monument to Nelson's famous victory at Trafalgar in 1805 (the monument itself was built in 1816). It resembles an upturned telescope and was designed by the architect Robert Burn. Once inside this impressive building, visitors may climb the 143 steps to the top and view Edinburgh in its entirety - behold the great 360 degree views of the city, across to the Firth of Forth, and over to Arthur's Seat, Holyroodhouse Palace and Edinburgh Castle. At the very top is a clever timed device that drops a huge ball to coincide with the one o'clock gun fired from the Castle - it was devised to enable sailors to check their chronometers.