With an overwhelming amount of research being published globally in a wide range of formats, locating and accessing relevant information can be a challenge. Although open access is an important tool for removing financial, legal and technical barriers to information, it is not on its own enough to cross the language gap between different cultures. Language plays a key role in participating in the global scientific community. Through multilingual metadata, information can be located and retrieved across languages so that resources indexed using one language can be retrieved using another. Finto is a service for publication and utilisation of ontologies, thesauri, vocabularies and classifications. It provides a user interface for browsing vocabularies and open interfaces for utilising them in other applications. The service also aims to provide high-quality metadata tools for the public sector. Finto is being developed as a joint venture between the National Library of Finland, the Finnish Ministry of Finance, and the Finnish Ministry of Education and Culture. Furthermore, in order to promote open science and free access to information, the service is being developed in an open manner and all its contents are available free-of-charge as open linked data. One of the main tasks in the Finto project is to develop General Finnish Ontology YSO in Finnish, Swedish and English. YSO is constructed by merging together the General Finnish Thesaurus and its counterpart in Swedish into a single hierarchical structure that explicitly specifies the concepts of a given domain and their relationships in a machine-readable format. Furthermore, the resulting ontology is translated into English and linked to the Library of Congress Subject Headings in order to link YSO with a global network of metadata. Working in a trilingual environment poses a number of language and culture-related challenges. As each culture conceptualises the world from its own viewpoint, meanings are seldom symmetrical across languages. Building a harmonious and understandable hierarchy in more than one language is a complex process and requires compromises. Moreover, translating the complete ontology into English and linking the concepts to LCSH involves connecting two very different languages together and requires a clear definition of an acceptable level of equivalence. This presentation illustrates the process and methods of constructing multilingual thesaurus and ontology services.