World Boss Sol Grande appears in Lost Ark at regular intervals of two or three days. As opposed to the game's other bosses, Sol Grande only appears on one island. But if your item level is high enough, you can come here whenever you like and take part in the activities. Read this and you'll know just where to look for Sol Grande in Lost Ark gold shop.

Getting to Sol Grande Commander-in-Chief of the World Found in the Ark of the Covenant
Located close to Arthetine, Sol Grande may be found spawning on Alteisen Island (or just Alteisen in-game). If you look south from the Arthetine port square on the map, you'll see the island. The port and Facility X-301 can be found in the upper left corner of this square, whereas Alteisen is located in the lower right.

The bosses of Lost Ark appear only at certain times and on certain days. In the beginning, all timers begin at the same time, and thereafter they cycle every few days. The following is a sample of the alarm schedule used by the global boss at Sol Grande.

You need to have the appropriate item level in order to take part in the combat against Sol Grande. Your minimum required item level to use Sol Grande is 1040. You can still do damage to the monster if you're below threshold, but it'll be harder to earn experience points and other prizes for your efforts. Simply press the letter "P" or navigate to Character > Character Profile to view your current level.

As soon as your item level is high enough, depart for the island from the dock in Arthetine and head southeast. You can try to avoid the sand for a time, but you'll have to go through it to get to the island anyhow because the Sandstorm Seas surround it. Auto-route to the island and hope for the best if your resistance to sandstorms is high enough.