Google announced today that it has updated Google Earth for desktop with 100,000 new tours and a million photos from Panoramio, a geolocation-oriented photo share site that Google acquired in 2007.

“As you navigate in Earth, tour guide acts as a local exploration expert, suggesting interesting places near the location you’re visiting,” Google said in a Google+ post announcing the update.

Google last added significant amounts of new imagery to Google Earth in October last year, unveiling 3D imagery for 21 global cities. At the time, Google said it had 11,000 tours, such as the one below of  Rome. The tours are not all terrestrial; you can also explore Mars, the Moon, or a variety of Hubble Space Telescope images.

100,000 new tours means that Google has created 89,000 in less than three months — a fairly staggering feat. The tours include fly-overs, Wikipedia snippets, and the photos sourced from Panoramio. Panoramio focuses exclusively on natural photos of the planet, excluding photos of people or vehicles, but allowing city scapes.

No software update is required to view the new content.

Image credit: Google

Weaving together pictures to make them worth more than a 1,000 words, Google has given life to more than 15,000 landmarks across the world with the release of photo tours for Google Maps.

Photo tours, released Wednesday, offers Google Maps users a three-dimensional view of thousands of famous destinations such as St. Mark’s Basilica in Italy, Half Dome in Yosemite, and the Eiffel Tour in Paris.

The tours, accessible from the Maps left-hand panel or landmark labels, fly folks around the historic and memorable locations using photos shared publicly on Picasa and Panoramio (a Google-owned community site for photos of places). Photo tours aim to offer viewers the most comprehensive perspective of a particular place, as seen from the masses that have captured and shared their experiences on other Google products.

Google constructs the tours by stitching together photos with computer vision technologies.

“We start by finding clusters of overlapping photos around major landmarks. From the photos, our system derives the 3D shape of each landmark and computes the location and orientation of each photo,” Google Maps software engineer Steve Seitz explained in a blog post on the new feature. “Google Maps then selects a path through the best images, and adds 3D transitions to seamlessly guide you from photo to photo as if you’re literally flying around the landmark and viewing it from different perspectives.”

The photo tours addition to Google Maps is just one of many ongoing improvements Google has made to the popular maps product in recent months. The company just added more traffic data and improved the Android version of the application. A few months back, Google Maps also rolled out 3D aerial route previews, providing users with a helicopter view of driving directions.