During a bout of terrible weather the party seeks shelter from the elements in a cave overlooking the road they have been traveling on. If the players blindly enter the cave with out scouting first they will find themselves immediately under attack. If the players take a moment to  scout out the location before they enter the cave  they will discover is not abandoned.  Hobgoblins are currently inside the cave and they seem to be guarding a sizable treasure chest brimming with coin.
But the coin is not their own; the weather drew the Hobgoblins here as well where they discovered this unguarded treasure. Who does the treasure belong to ? You have several fun things it could be after your players dispatch the Hobgoblins.
Maybe the adolescent dragon who is only beginning his hoard returns shortly after the party is done with clearing out the Hobgoblins.. Party’s got some explaining to do, or maybe this will be their first dragon kill.
Maybe the treasure is actually a Mimic waiting until the numbers are more in his favor to make a move.
Or maybe this cave that overlooks the road is the hideout of a group of bandits. And they come back that night.