“In the desert, the first thing man sees when he opens his eyes in the morning is the face of his enemy – the flaming visage of the sun. The sight elicits in him a reflexive gesture of self-preservation: he reaches for water. Drink! Drink! Only by doing so can he ever so slightly improve his odds in the desert's eternal struggle – the desperate duel with the sun.” (Rysard Kapuscinski)

The sea is invisible from Nouakchott. There is not even a hint that it's 5km away. In any other city this 5km would be prime real estate. In Nouakchott it's a wasteland. The city dumps it's rubbish here. Plastic bags find a home against thorny vegetation, until the wind changes direction and they trade places. I can't think of another capital city in the world that is so close to the sea, yet so detached from it.

I was asking my driver why this was so. He said he lived by the coast, but really his house was on the fringe of the city, before the 5km buffer zone of wasteland.

“We are a desert people, we don't like the sea. The land is also prone to flooding”.

Mr Sidi Ali is a French teacher in the International School here, although he studied English in Edinburgh for 4 years. There probably weren't many other Mauritanians living there in the early 1980's.

This was about the same time that slavery became illegal in the country. Many say it still exists. It was something I was interested in knowing more about, particularly after staying in Nouadibou and watching the way Abdullah, the pale-skinned hotel owner there, spoke to his Liberian employee.

Mauritania is a country where the caste system is clearly evident. The interaction between shop-keeper and customer reminds me a little of India. In Nouadibou I had stood in a small shop to buy bread whilst a new Mercedes pulled up. The shopkeeper ignored me when the driver, still in his seat, began ordering things. When his phone started ringing he answered it and indicated to the shopkeeper that he could continue serving me.

Mr Sidi Ali explained something about this as he drove me around the city. It didn't take long – the drive that is. Nouakchott isn't likely to feature any time soon on a recommended weekend getaway list. It's central landmark is a Saudi-financed mosque that sits opposite a sprawling mobile telephone market. The two slender minarets reach higher than the rest of the ugly concrete construction here. There is no park and the only greenery appears to be that surrounding the president's palace. What a surprise. Just like Nouadibou, the pavements and many of the roads here are filled with sand, although there are less goats, and at least in the centre, less visible rubbish.

The fish market is probably a highlight of a visit to the capital. Hundreds of colourful pirogues line the sandy beach, along which teams of dark leathery-skinned men are involved in some aspect of transporting the fish to a nearby open-air concrete bunker for sale. There are some monster fish here – 80, 90, 100kg+. I photographed one and a man soon came to tell me I must pay 500 ougiya (1.5Euro). I laughed and asked the dead fish if it minded.

Further along the coastal road is the city's port. It was built by the Chinese 30 years ago after the French said it was impossible to do so. The Chinese have a crew of workers who maintain it, just like the city's stadium. Whilst European financiers may invest money into a project then leave it to the local population to manage, it appears the Chinese favour a different approach.

An overloaded truck carrying refrigerators came past us on the road. One of many that transport second-hand goods coming from Europe to Africa. Nearby the port was a small black hill. On closer inspection it was an enormous mound of car batteries. “These will go to Japan for recycling”, explained Sidi. There were also dozens of cars, or rather parts of cars being cut up by crews of Senegalese men and loaded into containers. “They will also go to Japan. The Senegalese sell the metal to them for recycling”. It seemed resourceful and I wondered why the Mauritanians weren't doing this. “They don't want to. It is hard work”.

Alongside the road leading away from the port were small piles of what just looked like sand. Several women were sweeping the road. “They are collecting grain from the trucks”. This was a desperate scene. Wind-blown grain off the back of trucks coming from the port was being sieved and then loaded into sacks. I assumed it was for re-sale, but Sidi asked the elderly women who said it was for them. They lived in small wind-torn tents at the roadside.

Other than visiting the coastal fishing market, most of our tour was done within the security and comfort of Sidi's landcruiser. I wanted to explore on foot - walk through the central market area and get a better feel for the city. The problem is that Nouakchott, like Noaudibou, is strung out along roads that have little shade. Here you will see men standing or sitting and holding packs of cards. At first I thought they were lottery tickets, but somehow I don't think there is a lottery in Mauritania. These cards are mobile phone top-up cards. There are hundreds of men in the city selling them on the street. The cards are pre-paid – 500 ouguiya, 1000, 2000. I assume they must buy them in bulk at a discount price because you can also buy them in any shop. It makes little sense.

• There are several larger roads where you see lots of tools – shovels seem to dominate. Alongside them are teams of dark faced and ragged-clothed men. They sit in the sand waiting. Some might play a game with the shells that are easy to find on the roadside – a version of chequers perhaps? They are tradesmen – unskilled labourers or builders, plumbers, plasterers etc. They are waiting for a man much lighter-skinned than them to drive up and employ them – maybe for a few hours, maybe for a few days. None of them know. I saw this in Libya too.

Yesterday I had lunch with an Algerian man. I didn't know he was Algerian until he sat down at the same table as me in a small open-air eaterie and he told me a plate of rice and fish was 300 ouquiya. He introduced himself as Carlos, then explained he'd lived in Madrid before. He said he was a traditional doctor and I asked why he had chosen to live in Nouakchott for the last 14 years. “Don't use the word choice. There was no choice”.

We continued eating in silence for a few minutes before he looked up at me again. “I want to tell you something about Africa. It is a dangerous place”. I looked at the people at the tables around me. There was a young white moor wearing a starched white bou bou and listening to music from his phone. At another table two black men in shirts and ties looked like they might be on a lunch break from one of the nearby offices. A fat woman, the proprietor I guessed, was looking at me from behind. Moments later Carlos stood up, thanked me for the opportunity to speak with a 'real English man' and paid the woman before walking on out. How random I thought.

Tomorrow I'm leaving Nouakchott. The border with Senegal is comparatively close after the last 2000km of desert that has brought me thus far in Africa. Before leaving I must thank the teachers from the International School here, where I gave a presentation to students about my travels and the Against Malaria cause. They're rather incredulous that I can ride a bicycle through the desert and sleep in the middle-of-nowhere by myself. For me it feels strangely normal.

• I almost forgot to mention the visa. The passport disappeared for several hours along with 15 Euros. No questions were asked. Should I be inclined to remain in Mauritania until 15th March I can. Something tells me African bureaucracy won't always be such a smooth road on the way to South Africa. If you enjoyed reading this post don't forget you can receive it as an e-mail by subscribing to the newsletter, and can also follow shorter updates with my tweets. As I approach malarial Africa it would also be a great motivation to have some more support for the Against Malaria Foundation.