Romanesque architecture in Germany, Poland, the Czech Lands and Austria is characterised by its massive and modular nature. This is expressed in the Gothic architecture of Central Europe in the huge size of the towers and spires, often projected, but not always completed. The west front generally follows the French formula, but the towers are very much taller and, if complete, are surmounted by enormous openwork spires that are a regional feature. Because of the size of the towers, the section of the façade between them may appear narrow and compressed. The eastern end follows the French form. The distinctive character of the interior of German Gothic cathedrals is their breadth and openness. This is the case even when, as at Cologne, they have been modelled upon a French cathedral. German cathedrals, like the French, tend not to have strongly projecting transepts. There are also many hall churches (Hallenkirchen) without clerestory windows.