You really can't miss it, for Edinburgh Castle totally dominates Edinburgh's skyline, and goes a long way towards making Edinburgh known as the 'Athens of the North' into one of the most attractive cities in the world.
Edinburgh divides conveniently into the new Town which includes the famous Princes Street, and the Old Town which runs from the Castle downhill to Holyrood Palace.
The Castle is of course totally linked with the old town of Edinburgh, but to walk along Princes Street, with shops only on one side, and to be able to look up at the imposing Edinburgh Castle is an inspiring sight indeed.
It looks so imposing, and easy to see why it was impregnable.
Edinburgh Castle sits on top of the collapsed crater of an extinct volcano, and can trace its history back to the tiny Chapel of St.
Margaret, which is still in use, despite being the oldest building in Edinburgh.
Edinburgh castle has played many roles in its lifetime; apart from being a fortress, a military garrison, it has also been a state prison, but most notably of all it was once a royal palace.
Visitors today can still see the Crown Jewels of Scotland, known as the Honours of Scotland, which take pride of place as the oldest regalia in Europe, and include the Scottish crown, sceptre, and state regalia.
The Royal Chambers in the palace area of the castle were used until King James VI moved to England in 1603, and the Union of the Crowns made him King James I of England.
In fact James VI and I was born in Edinburgh Castle, the son of Mary Queen of Scots.
To this day at lunchtime, the One o' Clock gun sounds from the ramparts of the Castle.
It is a sound that echoes throughout Edinburgh allowing locals and visitors to reset their watches, and indeed generations of schoolboys to know how much longer their lunch break would last.
Every summer the famous Edinburgh Tattoo takes place on the esplanade of the castle and is not to be missed.
Put simply, if you visit Edinburgh and fail to visit the Edinburgh Castle, then you have missed out in a big way.