Giant tortoises, volcanoes, sharks, flamingos, marine iguanas, turtles, sealions and penguins - these hotel-based 4 & 5 day trips feature some of the best of the Galapagos islands' wildlife, marine life, and scenery. These trips are particularly good for topping up species and areas you may not have come across on a boat based natural history or diving trip. For those with only a short time to spare, they are also highly rewarding trips in their own right.

Southern Isabela, the Sierra Negra Volcano and the islets of Las Tintoreras are the common factor in all of these trips. With an extra day we can also take you to Los Tuneles at the far south western tip of Isabela: one of the best wildlife and marine life sites in all of the Galapagos.

If we first consider the central southern coast of Isabela, including its small offshore islands: sealions are the largest creatures we find here; very often right under our feet, so we have to take care to step around them. Marine iguanas are similarly littered in many places - on pathways through mangroves and along lava trails; but most rewardingly viewed on rocky shorelines, sometimes in their many hundreds draped over each other, reheating their bodies ready to go freediving for algae.  Las Tintoreras islands provides us with the best opportunities in the Galapagos we have of snorkelling with them.

Large Green Turtles are another snorkelling highlight at this location; and from above water we can often see dozens of sharks swimming in lava tunnels no more than 1 foot deep. On our 5-days version, mangrove systems and shallow caves further west provide us with some of the best opportunities to snorkel close to White-tip Reef Sharks, amongst schools of juvenile Golden Cownose Rays and yet more Green Turtles.

Back to the central southern parts of Isabela, salty inlets and pools amongst mangroves provide excellent habitat for flamingos, with easy opportunities to film and photograph them. Yellow legs, moorhens and Darwin's finches are also easily spotted in these habitats.

Of volcanic scenery, southern Isabela is home to a volcanic crater second only in scale to Tanzania's Ngorongoro Crater. Volcan Sierra Negra is 6 miles (10 km) across! To reach the closest point of the crater edge involves an overland drive and then a between 45 mins to 1 ½ hour hill walk. On a dry sunny day this can be relatively easy. When cloud comes in and there is rain, we have to pick our way more carefully. The summit can often be seen from the southern coast, but on days when cloud obscures a view, we can often trek above this layer for clear views across the crater. When you reach the crater edge, the scale of the landscapes is difficult to absorb.

The ultimate aim is to trek along the crater edge to Cerro Chico. This parasitic cone erupted spectacularly in 2005, just when the BBC were filming a series called Islands that Changed the World . Just beneath the surface, the rocks can be very hot, with lava tunnels running in all directions. It is essential to stick to marked trails here, because apparently solid rock can be very thin, with large voids beneath. The stark scenery here is very beautiful and views from this area extend far north to the enormous Elizabeth Bay and Fernandina Island.

Of other life, brightly coloured Sally Lightfoot Crabs can be seen in many locations on this trip; along with Lava Gulls, Nazca Boobies and Blue Footed Boobies. On our 5 days version, we can approach Blue Footed Booby nesting sites.

Photographically, wildlife and underwater video opportunities are wonderful on this trip. A GoPro or housing to a camera or video is recommended for snorkelling opportunities, whilst on land you would do well with wide angle, standard and telephoto capability.