Jungle Pylon

Pylons come from town NPCs rather than a workbench, and the sale has conditions attached. The seller has to be a real shopkeeper, which rules out the Traveling Merchant, the Skeleton Merchant and the Tavernkeep. Another NPC needs to be living close to them. You cannot be standing in Corruption or Crimson while you buy. Most importantly, stock follows the biome you are standing in, not where the NPC lives, so getting the Jungle version means bringing a vendor into the Jungle or doing your shopping there. Happiness used to gate this and no longer does.

You are also free to buy one and never place it, so it is normal to shuffle an NPC into a biome just long enough for the purchase and then move them back where you actually wanted them.

Placing it is only half the job. Both ends of a jump have to be live, and a pylon goes live when two or more housed NPCs live inside a wide rectangle centered on it. Town pets and the Old Man count toward that. The check looks at where their home tile sits rather than where they happen to be standing, though an NPC who has wandered a long way from home stops counting. On top of that the pylon has to be in its own biome, so a Jungle Pylon planted in a forest is furniture. Only one of each type exists per world, and the game gives no message when you try to place a second, the preview simply refuses to turn green.

You can travel by activating the pylon, which opens the full map, or by opening the map or minimap yourself and picking a destination. The minimap has to be enabled in settings or none of it functions, and you have to be reasonably close to a pylon to begin. One useful quirk: choosing the pylon you are already standing near teleports you to it, so any mine, arena or hole within its radius has a free ride back to the surface built in.

Standing in a mixed biome can put several pylons in the same shop at once. Forest and Cavern are the exceptions, since they exclude each other and only appear when you are clear of Snow, Desert, Ocean, Jungle, Hallow and Glowing Mushroom. A shop standing in the Jungle will never offer you either of them, so this is the only surface option in that spot. The Witch Doctor is a jungle resident and a legal vendor, which usually makes him the one you buy from.

The Cavern Pylon covers an enormous vertical band, so it is the one worth planning around. A cavern town just outside the Dungeon entrance gives near instant access to the deep Dungeon once Skeletron is dead, and you can build it beforehand, because the Dungeon Guardian only wakes when a player is actually inside, in front of unsafe dungeon brick walls. The Dungeon also sits next to an Ocean, so putting the Ocean Pylon on the opposite coast covers both. In multiplayer that layout can backfire, since a teammate inside the Dungeon lets Dungeon enemies spawn close enough to reach the town.

Dropping the Cavern Pylon low instead, near the Underworld, gives you a working substitute for a Hellevator early on. Once you can hold a town down there, an Underworld Pylon frees the Cavern one for something else.

This is a hub network, not door to door transport, so the rest of the kit still matters. Mirrors and Recall Potion handle the trip to spawn, the Shellphone and the conches cover both Oceans and the middle of the Underworld, and each pylon makes a natural terminus for a minecart line or, once the Mechanic is rescued, a Teleporter hub. The Universal Pylon breaks all the rules: it works anywhere, needs no NPCs nearby, and amounts to a reusable Potion of Return. It needs a complete Bestiary, which puts it after the Moon Lord.

Since 1.4.5 pylons work during boss fights and events. Older versions locked the whole network the moment something dangerous existed in the world, which was the single most annoying thing about them. The floating crystal is drawn on top of the tile rather than being part of it, so paint only takes on the stand. And with The Grand Design in hand and the overlay map open, clicking a pylon icon lays a line of wire from your position to the matching spot at the far end.