The 15-minute city has been establishing itselfin recent years as a model of both urban planning and urban design and is centered on some basic elements that define its basic characteristics. The elements that more than others define the concept of the 15-minute city are the proximity of a series of essential amenities (both public and private), walkability, the close relationship with at least one access point to fast and direct connections with other parts of the city, the presence of a lively life framework supported by medium or high density residence, a certain compactness of the settlement (which makes proximity to services possible), a certain diversification in the services supply. What we want to suggest in this contribution is whether it was possible to trace in the history of the city some period in which this concept of proximity, high density and diversification of amenities has established itself with a certain clarity in terms of urban planning. To this end, three cities of Roman foundation (Pompeii, Leptis Magna and Timgad) are analyzed with the aim of evaluating whether they can be considered X-minute cities: the lack of rapid means of transport, in fact, had forced Roman planners to think of urban models that could concentrate within a relatively limited space residence, amenities, efficient road infrastructure. In conclusion, some reflections are proposed on the effectiveness and performance of these city models and whether they can represent some useful reference for the urban design of contemporary cities and neighborhoods.