1. Kelburn Castle, Ayrshire Chris Townsend / geograph.org.uk / Creative Commons Kelburn Castle has been the seat of the Earls of Glasgow since 1350. In 2007, the current Lord Glasgow allowed four Brazilian graffiti artists to paint a giant psychedelic mural on the side of the historic castle. Historic Scotland initially said that the artwork could stay, but recently decided that it had to be removed. 2. The Dunmore Pineapple, Falkirk nl.wikipedia.org / Creative Commons This pineapple-topped 18th-century structure is widely considered the most bizarre building in Scotland. Originally built as a exotic plant hothouse for the fourth Earl of Dunmore, the Pineapple is now used as holiday accommodation. 3. Abandoned nuclear shelter, Edinburgh youtube.com This three-storey nuclear complex is buried deep beneath a hill in Edinburgh and was built in 1952 to house the Queen if she happened to be at Holyrood Palace during a Cold War attack. You can see a video of a team exploring the shelter here. 4. Edinburgh University Anatomical Museum, Edinburgh anatomy.mvm.ed.ac.uk / Creative Commons This museum is run by the anatomy department at Edinburgh University and is only open to the public on the last Saturday of each month. The museum is full of skeletons, curios, and historical treasures, including the death masks of notorious murderers Burke and Hare. 5. Goblin Ha', East Lothian Mr Smith / flickr.com / Creative Commons Goblin Ha', or Hobgoblin Hall, is a vaulted subterranean chamber hidden beneath the ruins of Yester Castle. The castle was built during the 13th century by Hugo de Gifford, nicknamed the Wizard of Yester by locals. He was widely thought to be a necromancer who carried out arcane rituals in the hall. 6. St Peter's Seminary, Cardross upload.wikimedia.org / Creative Commons This vast, decaying Catholic seminary near Glasgow is considered a masterpiece of European modernist architecture due to its spectacular use of light, space, and shadow. It's difficult to find as the site is hidden in the middle of an overgrown wood. You can see a video of a team exploring the ruin here. 7. Scotland's Secret Bunker, Fife John Allan / geograph.org.uk / Creative Commons Buried 100 feet beneath a farmhouse in Fife, this cavernous space was protected by heavy blast doors and would have housed most of the Scottish government in the event of a Cold War nuclear strike. It even contains a broadcast room for the BBC. The Ministry of Defence now runs it as a tourist attraction. 8. Rosslyn Chapel, Midlothian Flickr: landhere This 15th-century chapel has been widely rumoured to be the last resting place of the Holy Grail due to its intricate pagan, masonic, and Templar carvings. Before you dismiss that as fantasy, you should know that 3D scans have revealed an as yet unexplored secret underground chamber beneath the chapel. 9. Castle Sinclair Girnigoe, Caithness Flickr: santacruiser The twisted remains of remote Castle Girnigoe hide a secret oubliette used by the fourth Earl of Caithness to imprison his first-born son, John, after the latter rebelled against his rule in 1577. John died in the dungeon seven years later. There's some amazing aerial footage of the dramatic clifftop ruins here. 10. The Garden of Cosmic Speculation, Dumfries Flickr: emusing-emma The traditional grounds of Victorian mansion Portrack House were redesigned by visionary landscape architect Charles Jencks in the 1980s and renamed The Garden of Cosmic Speculation. The house and garden, with its strange, undulating landforms, lakes, and sculptures, are only open to the public for one day a year. 11. Maeshowe, Orkney Open Government License / scottishten.org Maeshowe is a spectacular Neolithic chambered cairn buried beneath a grassy mound on Orkney in the far ,orth of Scotland. The 4,800-year-old structure is considered one of the finest works of Neolithic craftsmanship ever discovered. During the Winter Solstice, the sun shines directly down the passage into the tomb. 12. The secret tunnels of Inchindown, Ross-shire RCAHMS During World War II, a series of vast oil storage tanks and tunnels were dug into the solid rock of a hill near the Invergorden naval base to conceal and protect the war fleet's fuel supply. In January this year it was discovered that the gigantic main tank has the longest echo in the world.