Lagos, a giant sprawl of humanity, is not for the faint of heart. It's dirty, expensive, crime-ridden, congested, hot and humid. Lagos is, however, the largest and oldest market city in West Africa and is certainly one of the most important cities on the continent—travelers who really want to get a complete picture of Africa should schedule a day or two there to simply drink in the chaos. On the southern coast near the border with Benin, Lagos consists of four major islands and several mainland areas (bridges and landfills link everything). This is one city where having an escort is very important—otherwise, you'll never really get a sense of what's going on around you (or the best way to get around). If you don't know anybody in the city, hire a car and driver.
Sights include the National Museum on Lagos Island (a fine but somewhat neglected collection of West African art), the Iga Idunganran (Palace of the Oba of Lagos), old Portuguese-style houses from the early 20th century and the modern National Theater. Upscale residential neighborhoods such as Victoria Island house the city's best shops and restaurants, though there are lively, less-expensive markets throughout Lagos. The safest (and cleanest) beach around Lagos is at Tarkwa Bay. There, you can watch the many hundreds of oil tankers line up to get into Lagos Harbor.
The old slave port of Badagry is an easy day excursion from Lagos and has some interesting, if not uplifting, museums dedicated to the slave trade. There on a sand bar is the Point of No Return—the last spot of African soil slaves stood on before being transported to the slave ships.
Day trips to Ibadan and Benin City are also possible.
For nightlife, King Sunny Ade (the best-known performer of West Nigerian juju music) performs Saturday night at his Ariya Nightclub when he isn't on tour. Femi Kuti, son of the late Afrobeat star Fela Kuti, carries on his father's music at the Shrine Club. On major Christian holidays—Christmas, Easter—you may see Carnival processions in the streets. These celebrations, called fantys, are traditionally put on by descendants of freed slaves who emigrated to Nigeria from Brazil.