City guide · 🏞️ Province
Layer-2 & Scaling District
A district for stand-alone chains that promise scaling but are not Ethereum L2s.
At a glance
| Who lives here | Small stand-alone chains in the L2 and scaling sector |
|---|
Coins of stand-alone chains that focus on scaling without being Ethereum L2s — chains using zero-knowledge proofs such as Mina, or scaling chains on the Bitcoin side — are gathered here.
Each chain has only its own coin, so they are grouped by sector (L2 and scaling). Ethereum’s own L2s stand separately in the capital region around the capital.
📰 The story of this city: Layer-2 & Scaling District: Standalone Chains, Not Ethereum L2s
The Layer-2 & Scaling District is where coins of small independent chains gather that promote ‘scaling’ or zero-knowledge proofs without being Ethereum L2s. Mina, Citrea, Fractal Bitcoin, Concordium, Firo, Pirate Chain and Ozone Chain live here.
Scaling chains that are not Ethereum L2s
Scaling means letting a blockchain handle more transactions faster and cheaper. On Ethereum the standard answer is the layer-2 (L2), which batches transactions and records only results on the main chain; large L2s form their own cities, and small ones gather in the L2 Suburbs beside Ethereum City (the capital). On the Crypto Nation map, this district holds coins of independent chains that promote scaling or zero-knowledge proofs without being Ethereum L2s.
These chains differ widely. Mina, Concordium, Pirate Chain, Firo and Ozone Chain are independent mainnets, Citrea is a zero-knowledge rollup on Bitcoin, and Fractal Bitcoin is a separate chain built on Bitcoin software.
What zero-knowledge proofs do here
A zero-knowledge proof (ZK) shows something is true without revealing details. Mina says recursive proofs keep its whole chain at about 22 KB, so users need not download the full history. Pirate Chain and Firo are privacy coins that hide senders, receivers and amounts, and Concordium builds identity into the protocol so users can prove, say, their age without exposing other data.
On the Bitcoin side, projects try to borrow Bitcoin’s security while adding smart contracts or speed. Citrea calls itself a ZK rollup that inscribes proofs on Bitcoin, while Fractal Bitcoin is described as a parallel chain that miners can merge-mine. Both are called ‘Bitcoin L2’ or ‘scaling’, but they secure themselves differently.
Uses and milestones
Mina, formerly Coda Protocol and started by O(1) Labs founders Evan Shapiro and Izaak Meckler, opened its mainnet in March 2021. The 2024 Berkeley upgrade brought zkApps, its zero-knowledge smart contracts, to mainnet. A notice dated 8 September 2026 says the ‘Mesa’ hard fork, approved by an on-chain vote in December 2025, has landed, cutting the slot time to 90 seconds.
Citrea, built by Chainway Labs, launched its mainnet on 27 January 2026 together with ctUSD, a stablecoin issued by MoonPay. Bridged Bitcoin (cBTC) pays its fees, and its token CTR, used for governance, reached major exchanges around late May 2026. Fractal Bitcoin opened in 2024, and Firo began as Zcoin in 2016 and took its current name in 2020.
Things to know
‘L2’ and ‘scaling’ do not imply equal safety. Citrea has been described as using a single sequencer (the server that orders transactions), and its Bitcoin bridge relies on an assumption, stated by the project itself, that at least one verifier is honest. Its mainnet is only months old.
Most chains here are small, with few users and apps, and compete with Ethereum L2s and large chains for developers and funds. Privacy coins face tightening rules over money-laundering concerns, and some exchanges have delisted or restricted them. Sharing a district guarantees no quality, and many write-ups are promotional, so check each coin separately.
Coins in this city
| Rank | Symbol | Name | Chain | Sector | Market cap |
|---|---|---|---|---|---|
| #843 | CTR | Citrea | Citrea | L2 & scaling | $19.5M |
| #237 | OZO | Ozone Chain | Own chain (small mainnets) | L2 & scaling | $126M |
| #291 | MINA | Mina Protocol | Own chain (small mainnets) | L2 & scaling | $92.7M |
| #449 | ARRR | Pirate Chain | Own chain (small mainnets) | L2 & scaling | $48.9M |
| #454 | CCD | Concordium | Own chain (small mainnets) | L2 & scaling | $48.7M |
| #516 | FB | Fractal Bitcoin | Own chain (small mainnets) | L2 & scaling | $41.2M |
| #898 | FIRO | Firo | Own chain (small mainnets) | L2 & scaling | $17.5M |
The coin list and market caps are as of the registry built on October 18, 2026. For live prices, weather and buildings, open the map. Crypto Nation is an unofficial fan project made by an individual. It is not affiliated with, sponsored by or endorsed by the Ethereum Foundation, CoinGecko or the teams behind the coins and chains shown; coin names and tickers may be trademarks of their owners. It does not recommend or rate any coin and is not investment advice. Prices come from CoinGecko and may be delayed or wrong.