Allan Quatermain is a 1887 sequel to Sir Henry Rider Haggard's famous and sensational novel King Solomon's Mines. Quatermain, an English-born Africa explorer of the Victorian era, is the explicit template for the Indiana Jones character. Granted, Harrison Ford is much younger and snappier than Quatermain, who in the Haggard series is an old professional big game hunter and trader based out of South Africa. This series kicked off what's called the Lost World genre, a thread that Edgar Rice Burroughs, Arthur Conan Doyle, and Michael Crichton would later take up.
In this adventure, our titular hero has lost his only son but is burning to get back into some action. He postpones his wedding and persuades some old mates to search for a lost (white) kingdom in East Africa. This action-packed story is well written and doesn't feel out of date at all. It contains daring fight scenes, terrible dangers, and spectacular escapes.