The aim of this essay is to present an alternative hypothesis about the localization of the ancient Indo-Roman port of Muziris/Muchiri, different from the current ones that would position it in Kerala, and precisely in Pattanam or Kodungallur, on the opposite side of the Periyar river. Obviously this proposal of an alternative localization does not in any way deny the archaeological findings of the current research carried out along the Malabar coast, which at that time was rich of many port of calls of the indo-roman trade, but only and specifically deal with ancient Muziris real site. The present study is based on two evaluations: u2022 The Pliny’s affirmation that the travel from Ocelis to Muziris lasted 40 days: as for the veridicality of this assumption let’s recall that he was the commander in chief of the Roman Fleet, stationed at Miseno Cape, and consequently he had all the means to collect reliable information both from military and merchant sources. u2022 The possibility of a simulation of the followed routes and time spent toward Muziris during the I century A.C., based on data about the Indian Ocean seasonally monsoons precisely evaluated by satellites, open the way for answering to the question "where are we after 40 days along those routes ?" There, Muziris was. PS The linked file Google_Earth_kmz_package.doc contains a list of places and courses, mentioned in the paper "Essay on an alternative localization of the Indo-Roman Port of Muziris". To see them obviously you need the Google Earth program on your PC, then: Open the file using Microsoft Word and Copy the package Muziris_10.kmz Paste it on any directory of your choice on the PC. Double click it and Google Earth will open showing courses and places described in the paper.