London is home to many museums, galleries, and other institutions, many of which are free of admission charges and are major tourist attractions as well as playing a <answer>research</answer> role. The first of these to be established was the British Museum in Bloomsbury, in 1753. Originally containing antiquities, natural history specimens and the national library, the museum now has 7 million artefacts from around the globe. In 1824 the National Gallery was founded to house the British national collection of Western paintings; this now occupies a prominent position in Trafalgar Square.
Besides being popular tourist destinations, London's museums play a vital role in what activity?
research