Sometimes it can be difficult to guarantee a safe spawn when your regular spawn point fails. Spawn Temple ensures a safe world spawn by generating a well-lit structure centered around the world spawn point. The structure is large enough to accommodate any spawn size - singleplayer, multiplayer, etc. At the center of the structure is a fountain, marking the exact spot of the world spawn.

Minecraft 1.10.2 is the original version and will likely work for all subversions of 1.10. The 1.12 port has been tested in 1.12.1 and 1.12.2 and should work in any other 1.12 subversion. Additional versions (even older MC versions like 1.8 or 1.6) may become available depending on user interest and/or personal motivation.

A few things to note:

There is no roof. This is because Minecraft will spawn you on the highest possible block. If there were a roof, Minecraft would spawn you on top of the roof instead of inside the temple. It's annoying, but so it is.
May impact other mods. For example, the temple will clear the entire sky above it. So if you have, say, Tinker's Construct and a slime island spawns there, the temple will obliterate it. Use judiciously.
This mod will run once. This mod should only ever activate when you first generate a new world. If you want to configure it, do so before creating a new world.

Features:

Optional full temple or simple fountain centered around the world spawn point
Multiple options for lighting system
Auto-generated approaches to the temple on all four sides (stairs and bridges and such)
Configurable building material for the temple/fountain
Configurable list of dimensions to generate the temple in

Config options:

causewayLength - If the approach is across water or lava, a causeway is generated, either until it hits land (non-liquid block) or this length is exceded. Set to a lower value if you have problems with the world generation.
dimensionsWhitelist - a list of dimension ids specifying the dimensions the temple will generate in. Note: Unexpected results may occur when generating in a scaled dimension (like the Nether) or in a dimension with a roof (like the Nether).
fullTemple - Whether to generate the full temple or just the fountain at the center
generateApproaches - Whether to generate the stairs, bridges, and causeways leading up to the temple's four doors
lights - The lighting options available, currently four:
- Torches - the basic lighting option
- Lava - A more impressive lighting system. Can set nearby wood/leaves on fire.
- Jack O'Lanterns - A fun system with a neat gimmick: the jack o'lantern on top of the fountain will always face north
- Glowstone - A more aesthetic lighting system
templeMaterial - The main building block the temple and fountain are made of. Can be set to any block (including blocks added by other mods) and will default to cobblestone if it doesn't recognize the specified block

Known Bugs (which I hope to fix at some point):

Sometimes light levels from light sources are not updated when the structure spawns.
Other world generation (ponds, trees, etc.) can sometimes spawn through the walls of the structure.
The structure destroys any entities under it (mobs, plants, even the bonus chest) and throws the contents on the floor of the temple.
The Dimension Whitelist was tested with and works with JED (Just Enough Dimensions). However, JED picks its own height for the initial spawn point (when a player enters the world for the first time), which is often inside the center post of the fountain. (The initial spawn point for a world is the same for every player, so if one player spawns fine everyone will.) (There may also be a JED configuration that can help fix that; I haven't investigated closely.) So if you're using JED, it's advised to send someone in in Creative Mode to fix the temple for future players OR just put up with a suffocation death being a player's first experience in the gameworld. Subsequent respawns work as normal.