Go through the portal
You stand at a crossroads in a land you have only seen in picture books. To your east, you see a mountain range, its peaks shrouded in mist. There are some caves about midway up the mountains, probably a day's hike away. To the south is a great city, its spires soaring and twisting in grand majesty. It seems to emit a glow, yet there is something profoundly disturbing about it, you just can not place your finger on what it is. To the west is an immense forest, both beautiful and terrifying at the same time. It has lived since before mankind was an idea in the great plan of the universe and will continue to be long after the world itself is gone. To the north is a vast sea, peppered with many different islands forming a huge archipelago. There is a small rowboat you can use to reach the closest island.