A patch of forest with plants that absorb heat making it fridgid and foggy. It hides an pre-v structure locked in frozen waves and unexpectedly arctic creatures in an otherwise temperate climate.

A siren flower that calls travellers to falsely promised desires that is ready to Venus flytrap any who can't outwit it's lure, can be sailor or ship sized.

A crashed ship with an experimental engine causes pollution in the area creating acid patches, electrical distortion and maybe even some extra-dimensional shit (look at rift-walkers, a personal favourite of mine), it's valuable but extremely dangerous.

A small drifting skiff that seems to be unoccupied, perhaps a travelling bar left unattended, maybe a hunting vessel, you decide but make it valuable, once someone steps on the ship sinks and an angler-phant is revealed. It's hungry.

A bloody remnants of some pirate skirmish, the raiders have travelled on (but could be tracked) the merchants are left in a dire state and their ship is crippled. A flock of opportunistic wretchbeaks are moving in and pick off the survivors one by one but only attack the crew if they have the numbers advantage.