The York House Water Gate: Part One - History of the Water Gate

The York House Water Gate, Embankment Gardens, New Year's Day 2012.

A 17th century Italianate arch lies 150 yards from the Thames, weather-worn and hidden between the office blocks.

In its pomp a gateway for kings and courtiers, it marked the riverside entrance to one of Europe's most sumptuous houses.

So how has it come to stand marooned in a park? And how did it survive the centuries?