From fortification to folly, this hilltop structure has undergone many changes in the last 800 years.

On a corner of the Ardmeanach peninsula on the Isle of Mull, a 50 million-year-old fossil tree hides in the coastal cliffs.

Considered "the most original, complete, and unimproved" circles in Aberdeenshire.

A 2,000-year-old Iron Age fort offers stunning ocean views.

A circle made up of 19 boulders has stood in Scotland's Bladnoch Valley for some 4,000 years.

It's believed a castle existed at this site since the 12th century.

No other place in Scotland has such a high concentration of prehistoric carved stone surfaces.

Now in ruins, this abbey was the home of Tironensian monks for more than 400 years.

The ruins of a 12th-century seaside castle on the southwest coast of Scotland.

Named for its similarity to the tip of a violin's bow, this striking formation was created by millions of years of erosion.

On a hill overlooking Loch Trool, a granite boulder marks the site where Robert the Bruce, King of Scotland, defeated an English army.

The overgrown ruins of this once majestic castle sit forlornly in the Scottish countryside.

The ruins of a 15th-century castle that has seen its fair share of bitter feuds.

Once considered one of the country's finest motte and bailey castles.

This Neolithic-era complex boasts standing stones, a cairn, and the only henge in Western Scotland.

Believed to be the birthplace of John Balliol.

This collection of Neolithic monuments make up one of The U.K.'s richest archeological landscapes.

This standing stone has a unique backdrop thanks to some of the United Kingdom's best-rated beaches.

Now in ruins, this castle stood for centuries and saw a number of gruesome events.

A 13th-century stronghold that has fallen into ruin.

Believed to be the smallest castle in Europe.

A historic fortification critical to Anglo-Scottish conflicts now serves as a bed and breakfast.

An 18th-century viewpoint across the surrounding highlands.

Legends surrounding this megalithic tomb range from giants to a dwarf named Trollid.