Sparta Base (Location)

Sparta Base is the name of a pair of surface bases owned by the Rangers and are the only known human settlements on the surface, during the events of Metro 2033 and Metro: Last Light. Located in Russian Orthodox churches on the surface, the iteration in 2033 is also simply known as "The Church" to residents of the Metro and the rangers passing through. The Last Light church is also known as "The Church Base" though is also never directly referred to as Sparta either. Artyom visits both bases in the games.

Metro 2033
The church serves as an outpost, resting location, and re-supply point for the rangers, and stalkers that wish to trade. Miller is the commander of this outpost.

The church has been fortified, with armored walls and metal gates/fences surrounding the perimeter and an airtight seal to keep radiation out. Inside Sparta, there is a communications outpost that attempt to contact the outside world, an armory run by Vladimir, a shop for the armored truck, refueling station for other ranger vehicles, and an entrance to an underground station leading to the metro with a steam-powered rail car.

During the game, this outpost serves as a refuge and rally point for the rangers heading towards D6 and the tower. When Artyom first reaches this outpost, he is greeted by Khan and the rest of the rangers, who are preparing for the journey to D6. Vladimir offers all his equipment to Artyom for free

Metro: Last Light
While the church in 2033 was located left of Polis, the church in Metro: Last Light is notably located in a much grander church south of Black Station, Polyanka. Last Light's Sparta base is as equally armored as the one seen in the first game. However unlike 2033's Sparta Base, the underground of Last Light's base is far more dangerous - although it does lead to the main Metro, the Rangers must first travel through miles of mutant-infested dark caverns, where the dead were buried for hundreds of years, using antique pulleys and lifts to traverse the caves. The ancient catacombs below are the perfect habitat for nosalises, and their brood mothers, which frequently attack travellers. Furthermore, after the bombs fell, the inhabitants seeking refuge in the church found themselves without food and left to find help underground. All those that died became ghosts, which still inhabit the crypt below, ominously ringing the church bells, calling for help that will never come. The only known exit into the Metro leads directly to Oktyabrskaya. It is in this church Artyom meets up again with Anna, after their separation during Ashes, as well as Lesnitsky. The resulting confrontation between the Rangers and Lesnitsky's men (dressed as Rangers) burns down much of the building, and the death of many rangers - likely permanently destroying the surface portion of the base.

Trivia

 * Both incarnations of Sparta Base include a windmill. The Rangers possibly use it as a power source for the Base
 * Artyom states in a note that some areas of the surface would actually be habitable were it not for mutants. The Rangers, being heavily armed, could easily fight against them should they get too close.