Open invitation to tender, deadline 02/09/2025, for technical assistance during monitoring and supervision of the tunnels Villabona 90I (902 M) and 90II (853 m) renovation project on the Leon - Gijon conventional gauge railway line. Click here for bid documents and here where tenders must be sent. Value of the contract is EUR 1.92 million, excluding VAT. Duration of contract will be 21 months. Contact Adif, Madrid, tel +34 91 300 76 61, email comprascontratacion@adif.es. Visit https://ted.europa.eu/en/notice/-/detail/408955-2025. Ref.n. 3.25/27507.0107. 27/25.