Explained: Pantheon AI's US$58bn Data Centre Campus

A transatlantic investment group has announced Pantheon AI campus, a project that could become the largest investment in Croatian history. The EU€50bn (US$58bn) facility is designed to address compute capacity constraints that could affect AI development across Europe.

Topusko, in Croatia – a central town with 945 residents near Zagreb – will host the 310-acre hyperscale AI data centre and innovation campus by 2027. The total investment equals US$58bn.

Pantheon Atlas is developing what the company claims to be among the largest private US investments into Europe. The facility design aligns with NVIDIA GW-Scale AI factory standards, positioning Croatia as a regional hub for AI compute infrastructure.

Europe's AI compute capacity gap

The project targets a structural capacity shortage across Europe's data centre market. Established data centre hubs across Europe operate with vacancy rates below 8%, while grid connection delays limit expansion potential.

According to Pantheon AI, electricity demand from data centres in Central and Eastern Europe is projected to grow three to four times by 2035. The region currently lacks a gigawatt-scale facility optimised for AI workloads.

Pantheon AI is addressing this gap with a design that integrates large-scale compute capacity above Tier IV availability. The campus will support up to one GW total capacity, with 800 MW allocated to IT load.

This scale could allow hyperscale operators to deploy high-density AI workloads that require sustained power delivery and advanced cooling systems. The facility is designed to support compute-intensive AI training and inference operations that require continuous uptime and fault tolerance.

Jako Andabak, Founding Partner at Pantheon AI, says: "Pantheon AI is a signal to the world that Croatia is open for the highest-calibre investment.

"This project is the culmination of years of work to bring world-class digital infrastructure to Croatia and we have assembled the deep local expertise, grid relationships and regulatory groundwork required to meet demand for data centre capacity."

The campus forms part of a transatlantic partnership that combines US investment with local technical and regulatory expertise. This structure provides access to grid infrastructure and planning approvals, both of which present challenges in European data centre expansion.

Power infrastructure for AI operations

Energy supply forms the core of the project's design for AI compute operations. Pantheon AI will bring up to 5.2 GW of renewable energy onto Croatia's national grid.

The planned site includes a 500 MW on-site solar plant operating behind the meter.

Power is generated and consumed directly without relying on public transmission networks, alongside 8,000 MWh of battery storage to stabilise supply.

The project's transmission infrastructure will connect through four independent 400 kV lines. This design supports both redundancy and capacity for Tier IV-level resilience required for continuous AI workload processing.

Underpinning the campus is its connectivity infrastructure with four independent fibre routes linking the site across three major European Union corridors. The GreenMed subsea cable aims to extend connectivity to Milan by 2028, with a network design that supports low-latency data transfer for distributed AI training and real-time inference applications.

Ryan Rich, Managing Partner of PantheonAI, says: "We have assembled a transatlantic partnership to solve one of the most pressing challenges in global digital infrastructure: enabling hyperscale operators to meet AI-driven demand at scale.

"We have lined up the power, fiber, regulatory stability and institutional support to solve that problem in Europe and we will establish Croatia and Central Europe as a premier destination for world-class digital infrastructure."

Strategic investment for AI development

The project was announced at the Three Seas Initiative Summit in Dubrovnik, Croatia. The event was attended by 13 presidents and prime ministers alongside the US Secretary of Energy, Chris Wright.

Joshua Volz, Special Envoy for Global Energy Integration at the US Department of Energy, says: "The race to lead in artificial intelligence is global and we are pleased to see American capital and investment expertise like Pantheon AI anchoring that leadership in allied, democratic nations.

"Critical infrastructure of this scale, built by the private sector responding to real market demand, is exactly how US interests and European security advance together."

If all goes according to plan, the construction of the EU€12bn (US$14bn) campus will begin in early 2027. Full operations are expected by the first quarter of 2029.

The wider EU€50bn (US$58bn) investment total reflects additional spending by hyperscale tenants as they install computing equipment and supporting technology for AI operations.

Sitting within 45 minutes of Zagreb and three nearby cities, the site provides access to a skilled workforce. It also has the expansion capacity to 450 acres.

Once complete, the campus will support 1,500 permanent roles and 3,000 construction jobs.

The facility could provide compute infrastructure for AI model training, large language model deployment and inference operations for European and international AI companies.