A place I love to go to is the Marianne North gallery at Kew gardens, London. The gallery is in a small quite plain building that doesn't hint at the wealth of work inside. The paintings aren't old masters, but there are some really lovely ones and what really makes it is the collection.
Marianne North was a Victorian naturalist and painter, who, on her father's death, set off around the world painting hundreds of paintings on her travels. She even collected wood panels from everywhere she visited and these decorate the bottom panels in the gallery.
Miss North travelled across many different continents painting a mixture of broader landscapes and in depth florals. Above is a distant view of Mount Fujiyama, Japan and below floral paintings from her trip to India
I find her sheer determination to paint everything she saw and the sheer volume of her work completely inspiring. I also love the way all the paintings are displayed in the gallery - I myself have a huge box containing over a hundred anzu paintings as well as a portfolio full of work and it would be great to see them all displayed at once.