The Indonesian island of Java has more people than Russia, Japan or Mexico. If it were a country, it would rank ninth in the world, with more than 150 million people packed into a space the size of Alabama.

We just spent ten days traveling across much of Java and saw crowded villages, towns and cities blending into each other. Traffic was intense, notably in the capital city, Jakarta, which has more people and vastly more motorcycles than New York, Los Angeles and Chicago combined. The traffic around our Jakarta hotel was so relentless that we were unable to cross the street without someone helping us.

Yet Java is also home to some of Asia’s most beautiful temples and cultural sites. It has lush rice fields, tasty food and natural beauty. It’s far cheaper to visit than neighboring Bali, where most foreign travelers head in Indonesia.

We enjoyed exploring Java with a local driver, Ari, who showed us lots of interesting places and took good care of us — all for a very affordable price.

As shown on the map, we started on the western side of the island, flying from Kuala Lumpur to Jakarta. One full day was enough there to see the main sites, including a national monument where we learned a lot about Indonesia’s complicated history.

From there, we drove to Bandung, which has “only” 2.5 million people, stopping along the way to visit the Tangkuban Perahu volcano, above, with its grey craters and steaming mud pots. Our hotel in Bandung surprised me with a cake for my birthday.

Next we took an all-day trip on a modern train to Semarang on the north-central side of the island. We spent most of the ride staring out the windows at endless fields, mosques, motorcycles, shops and schoolchildren. While touring Semarang, we met the students you see in the top photo, at a train museum. We were especially impressed by the Sam Po Kong temple, an ancient Chinese complex that has been extensively restored. We drank some refreshing fruit shakes while there, above.

We then headed south towards Yogyakarta, stopping at temples, tea plantations, waterfalls, volcanos and hiking spots, including one memorable walk through rice paddies to a beautiful temple.

The highlight in Yogyakarta was its two famous temples. Borobuder, above, is the largest Buddhist temple in the world. It features nine stacked platforms in the shape of a giant tantric mandala, all decorated with more than 2,600 relief panels and 504 Buddha statues.

Several miles away, the Prambanan Temple is the largest Hindu temple site in Indonesia, with an array of imposing structures whose stone carvings depict the epic Ramayana. We also enjoyed an outdoor dinner at a nearby restaurant with a breathtaking view of the temples lit up at night, followed by an excellent ballet performance of the Ramayana, above.

We also visited a sultan’s palace, a museum and other sites in Yogyakarta, including workshops for producing traditional shadow puppets, above, and batiks, below.

Yogyakarta was our favorite place in Java. It felt cosmopolitan but relatively livable.

We’re glad we traveled to Java even though parts of it, notably Jakarta, were a bit overwhelming. Java packs a lot of diversity, history and people into a corner of the world that gets little attention from Americans.

I’ll be posting next about Bali, which is far more familiar to many travelers. Yet Java has more than 30 times as many people as Bali. As we saw for ourselves, it’s not just its numbers that are so impressive but its beauty, people and overall vibe.

In every sense, Java is full of life.