Wyvern trenches on Fjordur location + accessibility

Fire (95.80 - 80.50 normal map) Easily accessible and enough space for you to maneuver in with larger mounts. Plenty of other dinos for wyverns to get distracted with after aggroing.

Poison (12.80 - 64.70 green portal) Beautiful trench ngl. But only accessible through a small entrance. Inside the trench is enough space to dodge attacks.

Ice (66.30 - 32.20 blue portal) One part of the trench is pretty easy to access, but if you want to check for more eggs you'll have to go through a small entrance. It's hard to dodge the ice wyverns breath within that part of the trench.

Lightning (30.10 - 08.20 yellow portal) Very hard to access. The trench is within a cave full of cave critters, and the trench itself is extremely narrow, making it hard for you do dodge wyvern attacks.

[I highly recommend using a Rock Drake for obtaining eggs. The rock Drake itself is easily obtained by stealing it's eggs with invisible Desmodus during night.]