Popularly known as Kovalam Palace, the Halcyon Castle was built in 1932 in the princely state of Travancore. This palace was constructed by M.R.Ry Sri Rama Varma ValiyaKoilThampuran, the consort of H.H. Maharani Sethu Lakshmi Bayi, as a retreat for the family. Now this heritage building has been converted into a heritage hotel.