In Belém, Lisbon’s most touristy neighborhood, one of the longest lines is not for the 16th-century monastery Mosteiro dos Jerónimos, but for the dark blue pastelaria next door. During the day, international and Portuguese tourists queue for hours to buy boxes of egg tarts at the takeaway counter or nab a seat in one of the five massive dining rooms. Egg tarts, in their modern form, originated here in 1837. Antiga Confeitaria de Belém's egg tarts are called pastéis de Belém, not pastéis de nata; the name is trademarked, and their original recipe is secret. Only six people alive today know that recipe, including the three master bakers who work behind closed doors at the so-called Secret Atelier.