Built in 1791 for the Earl of Dunmore, who also happened to be the last colonial governor of Virginia, this was his summerhouse. The walled gardens surrounding this strange building grew a wide variety of fruit — including pineapples. Pineapples were first grown in Scotland in 1731. Available to rent as a holiday home, despite this being a truly weird building, it has stood the test of time and there is nothing else quite like it!
Now famous thanks to the Da Vinci Code, Rosslyn Chapel is a masterpiece of medieval craftsmanship. Originally ordered to be built in the 15th century, by William Sinclair, the First Earl of Caithness, and abandoned in 1592, the chapel grew ruinous and derelict, until Queen Victoria visited and wanted it restored. Now it is a major tourist destination, drawing tens of thousands of visitors every year. Whether it contains any hidden treasures or relics should not really matter as the carvings themselves are treasure enough.
Constructed in 1862, this was a fine mansion house not too far from Pitlochry, originally known as Mount Alexander, built on the site of two former homes of the Clan Donnachaidh, both of which burnt down. It was requisitioned by the military during the Second World War, after which it was used to house refugees. It also caught fire and was abandoned in 1952. Now it stands as a shell, with birds and bats living in the towers, slowly crumbling. To make things even more creepy, there are two small graveyards hidden in the woods.