Natural History Museum, LondonThe museum originally started from a collection in the 1700s by the Dr. Sir Hans Sloane in the original British Museum location. Notorious for its nepotism in handing out staff appointments (even those that knew nothing about what they were doing) and inability to preserve the collections, many tens of thousands of items were lost.
In 1856, Richard Owen, a paleontologist, was appointed to be head of the natural history collections and changed the discipline and focus of the institution to be a respectable museum and petitioned for a location dedicated to the assemblage of items in 1864. The current building was completed in 1883 (nothing to be done well is done quickly). It has been in its current location on Cromwell Road ever since.
The Arrival - Gloucester Road Tube StationI alighted from the subway at Gloucester Road (instead of South Kensington, which is where you should) because I misheard the announcements about service at the next station. I then walked down Cromwell Road a while past many hotels and the French Embassy.
FossilsA massive collection of fossils, and really amazing pieces, including, well, Dinosaurs!
More Recent AnimalsPrimarily mammals and a lot of them. This is where the collection really stands out.
Main Hall and MineralsThis was the former main entrance, now is just an incredible wow factor and connection to most of the museum's halls.
Upper reachesThe top of the museum has a great section on the action that plate tectonics plays on our world, including earthquakes, hot springs and volcanos.
Other AreasSo there are other areas too, the storage of the collections' holotypes (used to evaluate a new item against to determine where it falls in the taxonomy), the Cocoon - a 4 story research and education center - the bugs section, an area on the impact of humans on our planet, and more!
SummaryFree, as are most government museums in London. Quite an impressive collection and series of galleries encompassing the history of our planet.
Located in an area with several museums (Victoria and Albert, Science, there are a few), it's a really great museum, but I will say I think the Field Museum in Chicago still wins the world's top spot for natural history museums.
Food is also available here, a great place for children. But as I am a big kid, I also enjoyed the many hours I spent in here. Easy access, free, it's a must do.