Although Twain would not have identified this as an amphitheater by looking at it:
The great theater of Ephesus is a splendidly preserved and very impressive building. This structure, built of marble, has a width of 145 meters, and its audience once reached up to 30 meters. In its heyday, it could accommodate up to 24,000 spectators.
A Farm of 240 acres, never referred to as a plantation. John Quarles had owned six slaves in 1840 and eleven in 1850, "many of them too old or too young to have been of much use on the farm." One in particular, Uncle Dan’l, might have been an inspiration for Twain’s character Jim.
Stonehenge is a prehistoric monument on Salisbury Plain in Wiltshire, England, two miles (3 km) west of Amesbury.