Hadrian's Wall, England...constructed in 122 AD to mark the northern border of the Roman Empire in Britain, the wall stretched across the width of Great Britain just south of the present day border with Scotland.
Okay, train travel in Europe is fun, but it's also kind of confusing. Where to buy tickets? When to reserve seats? Is 1st class all that different? Here's some advice on planning your trip through Europe by train.
Marble Caves of Patagonia in Chile – Lake Carrera. The lake is on the border of Argentina and Chile, and the caves are located on the side of Chile. The caves are the three main grotto: Chapel (La capillaries), Church (El Catedral) and Cave (Cueva). Visitors can explore the caves on a small boat or kayak, but only after the waters of Lake Carrera calm down and be serene.