Likewise, the cathedral is similar to those in Amiens and Rheims. The three of them have many details and features in common. In fact, the date of its construction has been deduced from the documents that indicate the dates when the French cathedrals were built. Amiens cathedral was built between 1220 and 1269 and Rheims cathedral between 1211 and 1241.

Leon cathedral has a cruciform ground plan. It consists of a nave, an ambulatory and five apses with their corresponding chapels. Apart from this, the cathedral has many other features in common with Amiens and Rheims cathedrals. First, the apse chapels are polygonal, and not circular. Besides, the transversal sections of the columns are alike, so are the details on the archs and capitals.

Leon cathedral is famous for its stained glass windows. There are more than 100 colours that fill the church with a multicoloured light.

Apart from the outstanding stained glass windows -some of which rise above 12 m in the apse- Leon cathedral contains many treasures, such as the choir stalls, made of black walnut from the 15 C, and the High Altar, from the 16 C. Behind the High Altar there are some frescoes from the 14 C that reflect an Italian influence.

Since 1964 the three chapels at the cloisters house the Catedralicio Museum, that can be visited from 9am to 1pm, and from 4 to 7 pm. The collection includes a variety of pieces, such as smithery from the 11 C, a crucifix carved by Juan de Juni in 1576, ancient codex, royal documents...