Minecraft - Multiplayer Server to Singleplayer?

So there's this multiplayer map, that i didn't create (its a public server) and i would like to find the perfect spot to build but i don't want to spend hours walking and trying to find it. Is there a way that i can convert this server into singleplayer, without having access the the world folder or anything?

There are mods out there that allow you to download the world file onto your computer. However, most require Forge. I won't list them all as I've forgotten their names but they are out there.