Otemon Gate, together with Tamon Yagura, forms Osaka Castle's grand main entrance. The gate you see today dates from the Tokugawa shogunate's reconstruction of the castle after the fall of the Toyotomi clan in 1615. It is built around a masugata — a square defensive courtyard designed to trap and disorient any attacker who made it through the outer gate.

Tamon Yagura is an imposing, corridor-style turret designated an Important Cultural Property. Its distinctive L-shaped layout was built to maximize defensive firing lines. Just past the gate, in the Oteguchi masugata courtyard, look for the huge stones known as Ote-mitsuke-ishi and Ote-niban-ishi.

Nishinomaru Garden occupies what was once the western section of the castle grounds and is now a roughly 6.5-hectare lawn garden. In spring, its approximately 300 Somei-yoshino cherry trees make it one of Osaka's best-known hanami (cherry blossom viewing) spots.

Three Important Cultural Property structures stand inside the garden: Sengan Yagura and Inui Yagura (both built in 1620), and Enshogura, Japan's only surviving stone-built gunpowder magazine (built in 1685). A separate admission fee applies to enter the garden.

Toyokuni Shrine — the sign at the site reads 豊国神社, read locally in Osaka as "Hokoku Jinja," the same characters read "Toyokuni" at its parent shrine in Kyoto — enshrines Toyotomi Hideyoshi, Toyotomi Hideyori, and Toyotomi Hidenaga. It was founded in 1879 as a branch of Kyoto's Toyokuni Shrine, originally at Yamazaki-no-hana on Nakanoshima island, and moved to its present site inside Osaka Castle Park in 1961.

The grounds include a bronze statue of Hideyoshi and a torii gate, and the shrine is popular with visitors praying for career success and good fortune. Goshuin (shrine stamps) and omamori (amulets) are also available.

Sakuramon Gate is the southern main gate leading into the Honmaru (the castle's inner citadel). It burned down during the Boshin War and was rebuilt in the Tokugawa-period style in 1887. Inside its masugata courtyard stands Takoishi ("Octopus Stone"), the largest stone at Osaka Castle — about 59 square meters of surface area and an estimated 108 tons, a granite block said to have been transported from Bizen Province (present-day Okayama Prefecture) in 1624.

On either side of the gate stand two more named stones, Ryu-ishi ("Dragon Stone") and Tora-ishi ("Tiger Stone") — according to local tradition, the outlines of a dragon and a tiger appear on their surfaces when they get wet with rain.

This underground exhibition hall lets visitors see the stone walls of the Osaka Castle that Toyotomi Hideyoshi built, up close. The walls had been buried and were discovered for the first time only in a 1984 excavation. After the fall of Osaka Castle in the summer campaign of 1615, the Tokugawa shogunate covered the Toyotomi-era castle with roughly 6 meters of earth and built an entirely new castle on top of it. In the underground exhibition hall, visitors can view the stone walls of the tsumenomaru (the innermost enclosure) through a glass floor, with multilingual explanatory panels.

The Osaka Castle Main Tower is the symbol of the castle. The present building was rebuilt in 1931 with donations from the citizens of Osaka, and now functions as an 8-floor museum tracing the life of Toyotomi Hideyoshi and the castle's history.

Exhibits include samurai armor, gilded roof tiles, and the Folding Screen of the Summer Siege of Osaka, and the top-floor observation deck offers sweeping views over central Osaka.

Gokurakubashi Bridge connects the Honmaru with the Ninomaru (second bailey) and is one of the best photo spots in the castle grounds, with the Main Tower reflected in the inner moat. According to tradition, the first bridge here was built in 1596 by Toyotomi Hideyoshi to welcome envoys from Ming-dynasty China. The current bridge is a 1965 reinforced-concrete reconstruction that keeps the traditional giboshi (onion-shaped finial) railings.

This makes a fitting place to end the route. From here, continue past Aoyamon Gate to reach Osaka Business Park Station (N21, Osaka Metro Nagahori Tsurumi-ryokuchi Line), about a 9-minute walk away.