Abe and Pena Nieto visited the pre-Columbian city of Teotihuacan yesterday with their wives Akie Abe and Angelica Rivera de Pena, donning palm-leaf hats and posing for pictures.
The couples did not speak with the press.
But Pena Nieto's office released a statement saying Mexico expects greater trade and cooperation with Japan in coming years.
Abe struck a series of energy deals Friday with Pena Nieto at the start of a five-country Latin American tour.
More From This Section
With Japan on the lookout for new power sources after the Fukushima disaster forced the shutdown of its nuclear reactors, energy is high on the prime minister's trip agenda.
Mexico is undergoing sweeping changes in its energy sector, with Congress poised to end struggling Pemex's 75-year monopoly and open up the oil and gas sectors to foreign investment.
Abe is the first Japanese leader to visit Mexico since Prime Minister Junichiro Koizumi did in 2004.
Abe's nine-day trip -- which will also take him to Trinidad and Tobago, Colombia, Chile and Brazil -- comes just days after China's Xi wrapped up his own four-country tour of the region.
With its emerging economies, Latin America holds promise as a relatively untapped market for Japanese exports, in addition to its coveted raw materials.