Requirements: level 15+
To access the event, click on its icon in the right-hand menu:

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 The Castle of Dona Chica, 8x6, can be placed anywhere

How to open chests
Each chest can be opened with 9 Ice keys.

There are 3 ways to get the Keys:
1. Complete the quests.
The quests appear in the left-hand menu one after another:

Delicious bouquets I
Collect 10 microphones (Pub)
Collect 7 hamburgers (Bistro)
Collect 9 nails (friends' cities)

Delicious bouquets II
Collect 7 carabiners (Subway station)
Ask friends for 6 repair kits
Collect 20 pencils (Stationery shop)

Delicious bouquets III
Collect 21 boots (Shoe shop)
Collect 17 lucky horseshoes (Convenience store)
Collect 22 satin flowers (Premium cottage)

2. Collect profits from certain buildings:
Central Station: 1 key every 24 hours
Paleontology museum: 1 key every 8 hours
Villa Masini: 2-3 keys every 24 hours
Hermitage of Mother of God: 2-3 keys every 24 hours
Hanau pavillion: 2-3 keys every 24 hours

3. Use the sale offer

Special offer:
Hermitage of Mother of God
(5x5, can be placed anywhere)