So much to visit here, (ignoring the Tatoo and Festival):

Holyrood Palace - one of the Royal residences. Not been myself, but reputedly quite good. Some nice walks nearby.

Edinburgh Castle - good value, but usually packed with tourists. The new display of militaria is very good and definitely worth visiting. Look closely and find the One O’Clock gun exhibit. The Camera Obscura and Whisky Heritage Centre are close by for a bit of variety.

National Museum Of Scotland - can be exceptionally good value if you take advantage of some of the ticket deals available.

Dynamic Earth - very educational but fun too, sometimes accussed of being a little overpriced, but I’m not so sure. Edinburgh’s version of D----yland, but without the rodent?

Edinburgh is not very car friendly - so it’s probably best to either walk or, better still, take public transport.