Merchiston Tower was probably built by Alexander Napier, the second Laird of Merchiston around 1454. It serves as the seat for Clan Napier. It is perhaps most notable for being the home of John Napier, the 8th Laird of Merchiston, inventor of logarithms who was born there in 1550.
Merchiston was probably built as a country house, but its strategic position and the turbulent political situation required it to be heavily fortified – with some walls as much as six feet thick – and it was frequently under siege. During restoration in the 1960s, a 26-pound cannonball was found embedded in the Tower, thought to date from the struggle in 1572 between Mary, Queen of Scots, and supporters of her son, James VI.
In 1930 the property became to the ownership of The Merchant Company, who used nearby playing fields for George Watson's College, which was soon itself to move nearby. Then in 1935 the tower passed to Edinburgh City Council. It remained unoccupied (except for war service) until 1956, when it was suggested as the centrepiece of a new technical college. Restoration work began in 1958, highlights of which were the discovery of the entrance drawbridge and the preservation of an original seventeenth-century plaster ceiling. It now stands at the centre of Napier University’s Merchiston campus.
The Tower is an interesting and elaborate example of the medieval tower house, being built on the familiar 'L' plan with a wing projecting to the north. It was originally vaulted at the second floor and the roof. Among several remarkable features is the unusual elaboration of the main entrance, which is at second floor level in the south front. The tall shallow recess in which the doorway is set undoubtedly housed a drawbridge which must have rested upon an outwork some 14 feet above ground level and 10 feet from the Tower.
Shortly after being let to Merchiston Castle School it was considerably altered with the addition of a castellated Gothic-style two-story extension and a basement, which has since been removed.
Napier University has taken out large sections of wall on the northern extension to accommodate a corridor which runs through the Castle to other campus buildings.References:
First record of Kastelholma (or Kastelholm) castle is from the year 1388 in the contract of Queen Margaret I of Denmark, where a large portion of the inheritance of Bo Jonsson Grip was given to the queen. The heyday of the castle was in the 15th and 16th centuries when it was administrated by Danish and Swedish kings and stewards of the realms. Kastelhoma was expanded and enhanced several times.
In the end of 16th century castle was owned by the previous queen Catherine Jagellon (Stenbock), an enemy of the King of Sweden Eric XIV. King Eric conquered Kastelholma in 1599 and all defending officers were taken to Turku and executed. The castle was damaged under the siege and it took 30 years to renovate it.
In 1634 Åland was joined with the County of Åbo and Björneborg and Kastelholma lost its administrative status.