Requirements: level 15+
In this event, you can open chests and receive guaranteed prizes from each of them.
There are 45 chests in total and rewards drop on a random basis.

The main reward is Trinity Episcopal Cathedral in Miami, size 6*8, can be placed anywhere
Every 24 hours: 4200 coins, 1-3 pearls/candies, 1-3 energy

Each chest can be opened with 9 Summer Keys
There are 3 ways to get the Keys:

1. Completing quests
Key quests will appear one after the other in the menu on the left side

Tidying the Laboratory I - 3 keys
Collect 7 screw wrenches (friends' cities, drop randomly)
Collect 9 Fire extinguishers (Water Tower, Upgraded Water Tower)
Collect 7 reinforcements (Cargo Port)

Tidying the Laboratory II - 3 keys
Collect 6 repair kits (ask friends)
Collect 20 pencils (Stationery Shop, Upgraded Stationery Shop)
Collect  21 jugs (Bakery, Upgraded Bakery)

Tidying the Laboratory III - 4 keys
Collect 17 valves (Premium Cottage)
Collect 22 pistons (Shoe Shop, Upgraded Shoe Shop)
Collect 10 spools of thread (collect wool, tulle, denim, printed cotton, linen, Venetian lace, silk, velvet, lace from Textile Factory; collect wool, felt, cashmere from Upgraded Textile Factory)

2. Collect profits from certain buildings:
Central Station: 1 key every 24 hours
Museum of Paleontology: 1 key every 8 hours
Petäjävesi Old Church: 2-3 keys every 24 hours
The Great Saint Martin: 2-3 keys every 24 hours
Pantanassa monastery: 2-3 keys every 24 hours

3. Purchasing keys from a special offer

Unique offer: Petäjävesi Old Church, size 7*6, can be placed anywhere

Every 24 hours: 4000 coins, 1-4 pearls/candies, 1-4 energy, 2-3 keys during the promotion