A bit of a circumnavigation spoiler, just in case you're an explorer and wanted to experience the unknown.
I made a bronze age ship to replace my stone-age raft. Huge improvement, with a 10 knot top speed and the ability to sail efficiently upwind...and to outrun sea serpents.
I decided to head north because it might be more interesting, I didn't want to go west and just end up in the east...I wanted to see if there was a limit or a border.
I sailed for two days and two nights, past a lot of black forest, swampland, and a couple plains biomes. I hit a biome called "mistland" that's a developer's work in progress. The sun and moon are nearly blotted out, most of the resources aren't harvestable, not much point in hanging around.
Further north, about 70 degrees N based on the round earth map, I started seeing glaciers. They literally have sheets of ice that slowly slide into the water, and fracture to calve icebergs. I am not making this up.
Now the spoiler:
I kept going north, right up to where the disc of the map appears to end. As I did, wind picked up to gale force from the south, the ocean started flowing north, and by the time I attempted to come about it was too late. The current sucked me over the edge of the terminal waterfall. I got a "you died" message as the freefall started, and ended up crashing on some surface hundreds of meters below.
My prize ship, my troll-skin attire, my best weapons, all gone to an unrecoverable grave. (Normally you can visit your death-site tombstone to retrieve gear...but this time I'm f**d.)
It was SO worth it. Bravo, Iron Gate!