Take to the waves and visit one of londons top attractions in style with this thames river cruise and greenwich royal observatory visit hop on and hop off your river sightseeing cruise from any of the four conveniently located piers as many times as you like for 24 hours cruise past famous landmarks including big ben the houses of parliament the london eye tower bridge and the tower of london and capture the views on camera then discover the hidden secrets of the cosmos at the famous r