Israeli researchers say ancient pollen deposits helped them reconstruct the layout of 2,500-year-old royal gardens near modern-day Jerusalem. The luxurious ancient garden would have been a centerpiece of Ramat Rahel, the only known palace dating back to the kingdom of Biblical Judah, scientists at Tel Aviv University said. Separating fossilized pollen from the layers of plaster found in the garden\'s waterways, archaeologists have been able to identify what grew in the ancient royal gardens and have been able to reconstruct the layout of the gardens, a university release reported. In addition to the expected local vegetation, such as common fig and grape vine, researchers said, exotic plants such as citron and Persian walnut trees grew in the gardens. These exotics were likely imported by the ruling Persian authorities from remote parts of the empire to flaunt the power of their imperial administration, they said. Another feature of Ramat Rahel\'s garden was its advanced irrigation system. Because there was no permanent water source at the site, rainwater was efficiently collected and distributed throughout the garden through pools, underground channels, tunnels and gutters. Researchers said the botanical and archaeological information collected would help in recreating the gardens so that visitors can experience the palace of Ramat Rahel.