Cities: Skylines rewards players for completing certain milestones (even bad ones) by allowing the construction of Unique Buildings. These are structures and buildings that can only be built once and offer many perks and boosts to your city. In addition to that, you need to build them before you can unlock Monuments. Here’s a list of the Unique Buildings, their costs, and what they can do for you.

Level 1 Unique Buildings

Statue of Industry

You Need: 10,000 squares of industrial zone built.

Cost: 20,000

Pollution: 0

Noise Pollution: 10

Upkeep: 320/week

Required for: The Eden Project

Statue of Wealth

You Need: 500,000 city money.

Cost: 25,000

Pollution: 0

Noise Pollution: 30

Upkeep: 400/week

Required for: The Space Elevator

Lazaret Plaza

You Need: Average citizen health under 20%.

Cost: 17,500

Pollution: 0

Noise Pollution: 25

Upkeep: 192/week

Required for: The Medical Center

Statue of Shopping

You Need: City money below -1.

Cost: 10,000

Pollution: 0

Noise Pollution: 25

Upkeep: 16/week

Required for: The Hadron Collider

Plaza of the Dead

You Need: Fill three instances of Cemeteries.

Cost: 17,500

Pollution: 0

Noise Pollution: 25

Upkeep: 80/week

Required for: The Fusion Power Plant

Level 2 Unique Buildings

Fountain of Life and Death

You Need: One full lifetime in the city.

Cost: 30,000

Pollution: 0

Noise Pollution: 25

Upkeep: 240/week

Required for: The Fusion Power Plant

Friendly Neighborhood Park

You Need: 10,000 squares of residential zone built.

Cost: 20,000

Pollution: 0

Noise Pollution: 25

Upkeep: 320/week

Required for: The Eden Project

Transport Tower

You Need: Public transport has 1,000 weekly passengers.

Cost: 60,000

Pollution: 0

Noise Pollution: 25

Upkeep: 960/week

Required for: The Space Elevator

Mall of Moderation

You Need: Average garbage piling per building at least 25.

Cost: 19,900

Pollution: 0

Noise Pollution: 35

Upkeep: 320/week

Required for: The Medical Center

Posh Mall

You Need: All tax rates at most 4%.

Cost: 45,000

Pollution: 0

Noise Pollution: 30

Upkeep: 960/week

Required for: The Hadron Collider

Level 3 Unique Buildings

Colosal Order Offices

You Need: Weekly education expenses 20,000.

Cost: 70,000

Pollution: 0

Noise Pollution: 10

Upkeep: 1,200/week

Required for: The Hadron Collider

Official Park

You Need: 10,000 squares of office zone built.

Cost: 45,000

Pollution: 0

Noise Pollution: 25

Upkeep: 128/week

Required for: The Eden Project

Court House

You Need: Crime rate over 50%.

Cost: 55,000

Pollution: 0

Noise Pollution: 25

Upkeep: 960/week

Required for: The Medical Center

Grand Mall

You Need: Construct airport.

Cost: 85,000

Pollution: 0

Noise Pollution: 30

Upkeep: 1,280/week

Required for: The Space Elevator

Tax Office

You Need: Construct Water Treatment Plant.

Cost: 18,000

Pollution: 0

Noise Pollution: 10

Upkeep: 320/week

Required for: The Fusion Power Plant

Level 4 Unique Buildings

Business Park

You Need: 20,000 squares of commercial zone built.

Cost: 80,000

Pollution: 0

Noise Pollution: 25

Upkeep: 400/week

Required for: The Eden Project

Grand Library

You Need: Construct seven instances of Universities.

Cost: 90,000

Pollution: 0

Noise Pollution: 10

Upkeep: 1,360/week

Required for: The Hadron Collider

Observatory

You Need: 1,000 abandoned buildings in the city.

Cost: 85,000

Pollution: 0

Noise Pollution: 10

Upkeep: 1,600/week

Required for: The Fusion Power Plant

Opera House

You Need: City extracts a total of 3,000 unites of natural resources.

Cost: 135,000

Pollution: 0

Noise Pollution: 40

Upkeep: 1,600/week

Required for: The Space Elevator

Oppression Office

You Need: Unemployment rate over 50%.

Cost: 80,000

Pollution: 0

Noise Pollution: 10

Upkeep: 880/week

Required for: The Medical Center

Level 5 Unique Buildings

Science Center

You Need: 5,000 full lifespans lived in the city.

Cost: 20,000

Pollution: 0

Noise Pollution: 10

Upkeep: 320/week

Required for: The Fusion Power Plant

Servicing Services Offices

You Need: Construct 300 city service buildings.

Cost: 20,000

Pollution: 0

Noise Pollution: 25

Upkeep: 320/week

Required for: The Eden Project

Aquarium

You Need: 5,000 children in elementary schools.

Cost: 20,000

Pollution: 0

Noise Pollution: 40

Upkeep: 320/week

Required for: The Hadron Collider

Expo Center

You Need: 2,000 tourists visit the city.

Cost: 100,000

Pollution: 0

Noise Pollution: 75

Upkeep: 1,600/week

Required for: The Space Elevator

High Interest Tower

You Need: 2,000 in debt.

Cost: 125,000

Pollution: 0

Noise Pollution: 25

Upkeep: 1,600/week

Required for: The Medical Center

Level 6 Unique Buildings

Cathedral of Plentitude

You Need: Construct all city service buildings.

Cost: 130,000

Pollution: 0

Noise Pollution: 35

Upkeep: 1,440/week

Required for: The Eden Project

Stadium

Cost: 200,000

Pollution: 0

Noise Pollution: 100

Upkeep: 4,000/week

Required for: The Space Elevator

MAM Modern Art Museum

You Need: 50% of the population highly educated.

Cost: 130,000

Pollution: 0

Noise Pollution: 10

Upkeep: 1,040/week

Required for: The Fusion Power Plant

Sea-and-Sky Scraper

You Need: Build a Passanger Harbor and a Cargo Harbor.

Cost: 20,000

Pollution: 0

Noise Pollution: 25

Upkeep: 320/week

Required for: The Medical Center

Theater of Wonders

You Need: Build three Universities.

Cost: 175,000

Pollution: 0

Noise Pollution: 25

Upkeep: 2,400/week

Required for: The Hadron Collider