The small Oldupai Museum on the rim of Oldupai Gorge stands on one of the most significant archaeological sites on earth. It was here in 1959 that Mary Leakey discovered a 1.8-million-year-old ape-like skull from an early hominin (human-like being) now known as Australopithecus boisei. This discovery, along with that of fossils of over 60 early hominids (including Homo habilis and Homo erectus) forever changed the way we understood the dawn of human history. Sadly, the museum is a work in progress.
An EU-funded museum has been under construction at the site for years, but work seems to have stalled – 2018 is the latest official estimate of when the new museum will open. Despite this, admission fees have risen massively in recent years, prompting some safari companies to encourage their guests to boycott the museum until the new museum is completed. Don't join the boycott, though: admission is indeed overpriced for what you get, but the site is still hugely significant and, unless you're likely to have the chance to return, it's a must-see.
In its unrenovated form, the small, two-room museum documents the foundation of the gorge, fossil finds and the legacy of Mary Leakey and her husband, Louis. One room is dedicated to Oldupai, the other to Laetoli. It's a fascinating collection, if poorly presented. You can then walk (or drive) into the gorge (where a small stone signpost marks the place where the fossils were discovered). You can also head out to the shifting sands, a 9m-high, 100m-long black dune of volcanic ash that has blown across the plain from Ol Doinyo Lengai. If you wish to take a guide it will, naturally, cost extra.
The turn-off to the museum is 27km northwest of Ngorongoro Crater's Seneto descent road, and from the turn-off it's a further 5.5km along a rutted track to the museum.