Lost Temple is a new zone unlike any other raid...
Lost Temple was released in the massive Jan. 21st patch. The entire map is essentially the final showdown with The Architect, the main villain and ultimate boss in Battle Camp's storyline.

This showdown comes in the form of a series of raids. Unlike the quests in other zones, these fights require your entire troop to participate. The Architect will pick an element, and your troop will have to complete a series of raids against monsters of that element. Each attack costs a player 3 energy. After attacking, the player then has to wait a few minutes before attacking again (the wait time varies between raids).

 

First Boss - 2 energy - 3 minute cooldown between turns - 4 hours to finish

Second Boss - 3 energy - 4 minute cooldown between turns - 6 hours to finish

Third Boss - 3 energy - 5 minute cooldown between turns - 8 hours to finish

Fourth Boss - 4 energy - 8 minute cooldown between turns - 10 hours to finish

Fifth Boss - 4 energy - 10 minute cooldown between turns - 12 hours to finish

Final Boss - 5 energy - 20 minute cooldown between turns - 14 hours to finish 

 

(these are not yet confirmed, please let me know if any are incorrect)

(This wait timer slightly decreases the power of gold on these raids, but gold can still make a difference - the timers are shorter than the 30 minutes it would take to naturally recover 3 energy).

Much like the raids on the Troop panel, there is a time limit for defeating each element's raids. Succeed in less time, and you can move on to the next element. If time runs out, you'll have to try the same element raids again from the start. Additionally, the entire area has a 7-day timer. When that timer runs out, your troop's progress is completely reset, regardless of how far along you were.

Once you've defeated all of the elemental raids, you fight the final boss. Beat him within the time limit to complete the Lost Temple.

Of course, you can always fight these battles again, and you'll need to if you're interested in 2nd evolution. 2nd evolution requires new ingredients that can only be acquired in the Lost Temple - Fire, Water, Leaf, Rock and Wind Crystals, and Super, Ultra and Epic Crystals. To perform a 2nd evolution, you'll need crystals of the element and rarity that match your monsters.