It depends on how much "science" a work of fiction needs to include in order to be qualified for the genre. Ancient epics like the Ramayana and Mahabharata mention flying palaces that could travel into space and underwater, and destroy entire cities. They weren't described "scientifically", but then again neither is Wells' Time Machine.

The Mahabharata briefly mentions time travel (or more precisely, time dilation).

There is also a long history of heavy exaggeration in travel literature. In the 5th century BCE, the Greek playwright Aristophanes described voyages to other worlds, and air travel.

In the 2nd century CE, Lucian of Samosata wrote True History which is sometimes regarded as the first work of science fiction (S.C. Fredericks, Lucian's True History as SF) since it includes themes like travel to outer space, alien life forms, robots, etc.

Thomas More's Utopia (1516) is set in a far-off land (or maybe a place in the future) of free religion, premarital sex, and even divorce; Of course, there is some controversy of why More wrote it, seeing as he was a devout - or maybe zealous would be more accurate - Catholic.

hi! FYI, you'll find some previous discussion in the FAQ (link on sidebar)

What was science fiction like in the past? How did ancient people imagine the future?

Al-Risalah al-Kamiliyyah fil Siera al-Nabawiyyah, known in Europe as Theologus Autididactus, is regarded as an early example of science fiction from the late 13th century, though it's also a philosophical novel and a response to Hayy ibn Yaqdhan, a similar novel about a man generated from nothing written by ibn Tufail.

Gulliver's Travels by Johnathan Swift contains a number of science-fictional elements, including a depiction of a tyrannical king who rules from his magnetically-levitated flying city and puts down rebellions by dropping rocks on those rebellious cities below.

Natural philosophy fiction, to be more precise. ' Natural phi-fi.