A private collection of massive steel monsters guarding a Texas pipe works.

A small stone pillar marks the spot where Mary, Queen of Scots, spent her final hours as a free woman.

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

Sculptures depicting Scottish and English soldiers in battle honor a 16th-century conflict.

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

The recurring nature of this geographic feature might make it unique in the world.

This 900-foot structure with 20 arches crossing a Scottish river was built in the late 19th century.

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

Scotland is filled with standing stones that date back hundreds or thousands of years. This is not one of them.

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

Stone monkeys adorn the buildings of this former estate.

These formal gardens were designed to be admired from the vantage point of the castle.

It's said this was once the home of King James V's pet lion.

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

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

A tumbling waterfall near a narrow passage that was used to herd cattle for hundreds of years.

Reportedly the "most handsome" market cross in Scotland.

The fictional birthplace of the Chief Engineer aboard the Starship Enterprise.

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

This impressive midden of scallop shells apparently all comes from a single fishing company.

This man-made waterfall was designed to help improve access for spawning salmon.

This city square dates back to the Scottish Enlightenment and was home to some of Scotland's brightest minds.

This pyramid is dedicated to all those who suffered martyrdom for civil and religious liberty in Scotland.

This uniquely shaped rock formation is one of Scotland's most iconic mountains and gives spectacular views in all directions.