Massive underwater breeding pen. Can comfortably hold 9 Mosa's and have plenty of room left over.
Total Resources required when you puzzle piece the build together:
40,740 Ingots
11,426 Paste
28,920 Crystal
5,610 Polymer
600 Wood
368 Element
This looks like a lot, but I can gather all resources in 1 hr when grinded correctly.
Metal Ingots: TheCenter: Will gain 40,000 in 20 minutes when using Dunkleo in ocean trench.
Paste: Gen1: Cheaper By The Pack mission when ran twice will grant 16,000 paste from hex shop. (6 Minutes total)
Crystal: TheIsland: Hunter Cave, use a tek suit, will slot cap inventory in 5 minutes
Polymer: Lost Colony: Use a bear, harvest the light blue plants in corrupted zones will slot cap bear in 8 minutes
Element: This is up to you, I ran Hydraskos. Easy tributes, I cheesed it in 3 minutes with 2 100k HP stegos and 1 2,400 melee deino. Takes 20 minutes to prep assuming you already have necessary tames.