Lima: As the capital, Lima boasts the most robust mobile coverage in Peru. Expect strong 4G/LTE signals across key districts like Miraflores, Barranco, and San Isidro. Connectivity on the Metro de Lima is generally good on the elevated Line 1, but can be intermittent on the underground sections. Indoor coverage in modern buildings is reliable, though signals can weaken inside some older, colonial-era structures in the historic center.

Cusco: In the urban center around the Plaza de Armas and in tourist-heavy areas, you'll find dependable 4G service. However, due to its location in an Andean valley and its historic stone architecture, indoor signals can be weaker, especially in hotels with thick walls. As you travel to nearby attractions in the Sacred Valley, expect coverage to be strong in towns like Ollantaytambo but spotty or non-existent in the rural areas and on transport routes between them.

Arequipa: Peru's second-largest city offers solid 4G coverage throughout its main urban areas. The historic center, a UNESCO World Heritage site, is well-covered outdoors. Be aware that the city's signature white "sillar" volcanic stone, used in many older buildings, is very thick and can significantly reduce indoor mobile signal strength. Connections are typically strong in the more modern districts of Yanahuara and Cayma.

Trujillo: This northern coastal city has reliable 4G connectivity within the city limits, including its historic core. Service is generally good for day-to-day use and navigation. When visiting the nearby vast archaeological sites like the Chan Chan complex or the Huacas del Sol y de la Luna, signal can become less consistent due to the open, sprawling nature of these locations just outside the primary urban infrastructure.

Pan-American Highway (PE-1): Coverage is generally strong along the coastal Pan-American Highway connecting major cities like Lima, Trujillo, and Arequipa. However, expect signal to weaken or drop in desert sections between towns. Roads into the Andes, such as the Carretera Central (PE-22), have highly intermittent service that is often lost for long periods.

Andean Railways: Tourist trains like PeruRail and Inca Rail from Cusco to Machu Picchu maintain cellular signal in the Sacred Valley towns but lose it in the remote canyons approaching Aguas Calientes. The Ferrocarril Central from Lima to Huancayo, one of the world's highest railways, has almost no connectivity for the majority of its high-altitude journey.

High-Andean Passes: Signal is consistently lost when crossing high-altitude mountain passes. Expect zero coverage at famous points like Abra Ticlio on the Carretera Central (over 4,800 meters) and Abra La Raya between Cusco and Puno. Service typically returns only upon descending into populated valleys.

Amazon Rainforest and Highlands: Connectivity is almost non-existent in the Peruvian Amazon outside of major cities like Iquitos and Pucallpa. Similarly, in the Andean highlands (sierra), service is limited to towns and villages, with vast areas of mountains and plateaus having no signal at all.

Tunnels and Canyons: Most highway and railway tunnels, particularly the numerous ones on routes climbing into the Andes, do not have cellular repeaters and are complete dead zones. Deep canyons, such as the Colca Canyon or the Urubamba River canyon, can also block signals effectively even when you are not in a tunnel.