Been to a few exhibitions recently and If you haven't been yet I seriously suggest you try and visit The Scottish National Gallery of Modern Art One to see their current exhibition titled "From Death to Death & Other Small Tales. It's on until the 8th of September and is well worth a look (also is free).
Truly an eclectic range of works to be seen which are well worth seeing (Duchamp's Fountain for me in particular).
Secondly Man Ray Portraits, located at The National Portrait Gallery is also a very exciting exhibition especially for anyone interested in photography which I'd recommend going to (costs £5 but still); gives you an insight on the transition he went through from his time in Paris and America and his experimentation with different techniques.
