Keep

This Building and eventually the main heart of your starting empire will contain all sorts of upgrades and improvements. You can level up your thriving society at it to slightly improve your handcraft skills.

Keep I
Agriculture I - Cost: 356 logs, 285 stone, 127 hay. Improves condition for animals, crops and trees and accelerates their reproduction and growth.
 * Agronomy I (requires Agriculture I) - Cost: 110 stone, 81 ore. Accelerates crops and trees growth on fields and orchards.
 * Animal breeding I (requires Agriculture I) - Cost: 158 logs, 59 hay. Accelerates cattle reproduction.
 * Forestry I (requires Agriculture I) - Cost: 118 logs, 42 clay. Accelerates tree growth.

Production I - Cost: 415 logs, 332 stone, 155 hay. Reduces production time for resources. Production II - Cost: 831 logs, 665 stone, 486 ore, 297 clay. Reduces production time for resources.
 * Food Production I (requires Production I) - Cost: 134 stone, 62 hay. Reduces production time of food in the Bakery (doesn't impact windmill).
 * Tools Production I (requires Production I) - Cost: 178 logs, 104 ore. Reduces production time of tools.
 * Ore Mining I (requires Production I) - Cost: 118 stone, 86 ore. Reduces time for mining ore, stone and clay.

Tech Tree
Each row of the technology tree must be completed before progressing to the next. However you can complete one tree (agriculture or production) without touching the other.