The spectacular 17th-century wooden "Peace" churches of Swidnica and Jawor are both listed as UNESCO World Heritage Sites and have provisions for English-speaking visitors (written information and an English audio tape they will play in the church on request) that are often frustratingly lacking at other tourist destinations in Poland. The "Peace" in the names refers to the Peace of Westphalia of 1648 that ended the Europe-wide Thirty Years War. Though the war finished inconclusively, this part of Europe fell under the domination of the staunchly Catholic Habsburg Empire, ruled from Vienna. Local Lutherans sought the protection of the King of Sweden for the right to build three Lutheran churches in the area (a third church at Gogów later burned to the ground). The Habsburgs relented but stipulated that the churches could be built only under very difficult circumstances: They had to be constructed completely from wood without the use of iron nails, located outside the town walls, and completed within a calendar year. That the churches were finished at all was a miracle; that they turned out so beautifully is fitting testimony to the faith of the believers. The Swidnica church, which can hold up to 7,000, is the largest wooden church in Europe, but both structures are amazing in terms of their size, the engineering skills that went into their construction, and their enduring beauty.