linguistic:paraphrasing, structural:reformatting
Antiquity

Stadiums in ancient Greece and Rome were built for different purposes, and at first only the Greeks built structures called "stadium"; Romans built structures called " circus ". Greek stadia were for foot races, whereas the Roman circus was for horse races. Both had similar shapes and bowl-like areas around them for spectators. The Greeks also developed the theatre, with its seating arrangements foreshadowing those of modern stadiums. The Romans copied the theatre, then expanded it to accommodate larger crowds and more elaborate settings. The Romans also developed the double-sized round theatre called amphitheatre, seating crowds in the tens of thousands for gladiatorial combats and beast shows. The Greek stadium and theatre and the Roman circus and amphitheatre are all ancestral to the modern stadium.