The Trivandrum Observatory or Thiruvananthapuram Astronomical Observatory is a scientific and astronomical observation station that was established by the Raja of Travancore Swathi Thirunal Rama Varma in 1836–37. The Raja wrote to the British Resident, Colonel James Stuart Fraser, an amateur scientist proposing the establishment of an astronomical observatory. This led to John Caldecott who earlier ran a small personal observatory at Alappuzha being appointed as the royal astronomer. The observatory was located on the highest point in the city and opposite the palace and was considered important as the magnetic equator at that time passed through Thiruvananthapuram. The observatory was designed by Lieutenant W H Horsley of the Madras Engineers.