Fallout 1 is a great game, but the way it's structured (with the world map travel) it doesn't really lend itself well to exploration, in my opinion. You basically find locations of interest by talking with NPCs, or by passing near them on the world map, and then go there
Fallout has better exploration than Baldur's Gate for a number of reasons:
-every location in the world can be accessed from the very start, unlike Baldur's Gate, which plot-gates big chunks of its areas, most notably the titular city of Baldur's Gate;
-there are time limits for the water chip quest and the mutant invasion, which, while still lenient, make the player at least think somewhat about what locations to go to;
-Fallout abstracts it world into a world map which makes it possible to stumble into areas purely by accident and makes the player at least pay some attention to what direction to head to. Exploration in Baldur's Gate is a simpler process of methodically exiting a map from different directions to unlock the next areas;
-hidden/special encounters while traveling - Baldur's Gate doesn't have these;
-exploration of the world allows the player to better deal with the antagonist (for example the Brotherhood's holodisk that reveals the Super Mutant's sterility).