MAPULA LODGE: In an exclusive Botswana safari camp where Prince Harry took Meghan Markle on a romantic getaway last year, guests wake to the sound of doves cooing in the trees and hippos splashing in the serene waters of the Okavango Delta.

Harry whisked the American actress away last year for a surprise holiday to celebrate her 36th birthday, hopping between luxury resorts in the sparsely populated southern African country renowned for its stunning wildlife and sweeping vistas.

The trip last August came a year into their relationship and a few months before they got engaged. Their wedding on May 19 is building up to be the social event of the year.

Harry sourced the diamond in Meghan's engagement ring from Botswana, the world's biggest producer.

The couple went to Botswana soon after they began dating in July 2016, a trip Harry described in a media interview last year as a "crucial" chance to get to know each other.

Their subsequent visit to the Okavango Delta last August has been kept a tight secret, with Kensington Palace and lodge managers declining to comment. But Reuters spoke to two local insiders who described the romantic escape.

At Mapula Lodge, an isolated $800-a-night retreat that translates as "mother of rain", Harry and Meghan slept in a traditional thatched cabin with an outdoor shower, their carved wooden bed looking out over a pristine lagoon.

The couple enjoyed a sunset cruise along the creeks that wind through the vast grasslands, stopping to try their hand at fishing. Harry caught a sharped-toothed catfish as he and Meghan shared a joke, one onlooker said.

"They are like regular guys. They were just relaxed," the person said. "You could see they were very happy together."

On an early morning game drive, the couple scoured the horizon for the wild animals that are the primary draw for wealthy clients visiting the Okavango, one of the largest inland deltas in the world.

In the most romantic offering at the camp, Harry and Meghan were driven out at twilight to a deserted area of the bush to the foot of an ancient baobab tree where they were served a three-course meal beside a glowing fire.

When they departed, Harry dealt out generous tips and one staff member shed a tear while waving the couple off from the resort's private airstrip, the sources said.

RICH AND FAMOUS

Botswana is popular with the rich and famous because of the privacy and isolation its top end lodges offer. Other recent visitors include former US President George W Bush, Saudi princes, Hollywood stars and millionaire footballers.

"They all come to Botswana because it's still a nice destination to go to where you're not bothered about paparazzi because you're far away from anything and everything," said Eric Muizebelt, manager of the nine-room Mapula Lodge.

"The people from Botswana are not like: 'I want to have an autograph or a picture'. People can come here and have their complete rest and peacefulness."

Before venturing into the Delta, Harry and Meghan spent a night at Meno a Kwena - meaning "teeth of the crocodile" - a camp of luxury tents overlooking the Boteti river where guests often hear the roar of lions during the night

Harry brought his then girlfriend, Chelsy Davy, to the same camp in 2007.

"It's an extremely romantic destination," said Hennie Rawlinson, owner of Meno a Kwena, where chefs prepare food over an open fire and guests dine al fresco.

"Almost every night we have a spectacular sunset. You find you are the only person in the wilderness."

Botswana, a country of around 2 million spread over an area the size of France, has always been a place of solace for Harry.

He first visited when he was 13, two months after his mother Princess Diana died, and he has returned several times for leisure and charity work. This year he became a patron of Rhino Conservation Botswana, a long-held passion of his.