Do you know what this television programme or film was?

I saw this television programme or film showing on television (I’m sorry that I sound repetitive, I just wanted to make clear what I am talking about) when I lived in England when I was very little, from the year 2000 (when I was four) to the year 2003 (when I was seven), but I believe that it was either in 2001 or in 2002. I cannot remember the beginning credits; I only realised shortly after I started writing this. (Originally, I wrote “that as I was writing this just a few seconds ago”, but a few months have passed since then – my father saw that I had given away too much information about where we originally lived in England when I originally wrote this question, and so he didn’t allow me to finish it). {The sentence that was in the brackets I actually again wrote a few months ago – I couldn’t upload this question onto Fluther, as I couldn’t create a new Fluther account, as my e-mail address was still recognized as belonging to my old account, and my old account was deleted by my sister, due to it revealing too much information. Fortunately, my e-mail account has been reactivated, having written to Fluther about it, although I was intending to get a new account rather than the old one.} [I have written the above around one or two dozen minutes ago – I can’t remember – and I am uploading to Fluther now. I didn’t before because I was thinking about what to add to my question.]
I thought the first scene I saw (or, at least, what I thought was the first scene of the show; I might have seen a scene or scenes previous to that – I think I have a poor memory) was the beginning of the programme or film, but I realised it can’t have been. The scene I thought was the first scene had a boy, possibly a teenager (I thought he was a teenager for years, but I thought late last year or earlier this year that he may have been younger), falling down from the sky, perhaps through a portal, into a desert – I thought it was the Sahara, I believed it was in the future.
Soon afterwards, he meets a girl of his own age (I always thought it was his own age, she looked like it) who was dark-skinned and wore traditional clothing, although I cannot remember what the clothes were, and in retrospect, she spoke with an accent, I presume a Sub-Saharan African accent (I apologize for sounding crude, but that the best way I can describe it), and she might have had companions who looked like her and had the same accents as her (I apologize or sounding crude again, and I know this might sound repetitive again, but that was the best way I can describe it), and she and, if she was not alone, they, might have had spears. I believe they introduced themselves to each other – I believe the boy introduced himself first and then the girl introduced herself – and she might have told him that she will take him to her village – she must have because it showed them arriving at her village, which had round thatched huts, I believe. I do believe she must have introduced him. Her father might have been the chief of the village, or he may not, and he may not have been shown at all. At some point, maybe when the boy meets the girl or when she takes him to her village, he states that he is looking for his uncle. I do believe that someone, maybe the girl or someone at the village, or, as I realised a few seconds ago, one of the girl’s companions, if she had any, told the boy that people, maybe he or she said children, but I am not sure, had been kidnapped by monsters.
The monsters may have come that night and kidnapped more people or children, if they only kidnapped children, and possibly the girl, but I am not sure. The next day – I thought for years it was the next day – but it might have been later he goes in search of the monsters with a companion or companions, possibly the girl if she was not kidnapped, and they enter the monsters’ lair – I might have seen them entering a cave in the desert, possibly covered mostly by sand, and as they walk continue walking, three monsters, which are toad-like, drop down from near the ceiling (they were on a ledge) near the entrance, quickly one by one, from left to right, and later they attacked the boy and, if he had any, his companions. The boy and, if he had any and, if they weren’t captured, his companions, go/goes into a room – a part of the cave – and sees a group of unconscious people or, if the monsters only kidnapped children, children, tied up with rope, or perhaps in webbing of some sort, or perhaps in a mud-like substance which was a grey colour, and possibly tied to stalagmites (the ones at the bottom). If there was a mud-like substance, it might have been a part of the stalagmites, or at least it was the same colour or a similar colour to them. The girl might have been there, unconscious and tied up, if she was kidnapped during the night or when she was accompanying him, and if his companions were captured at that point, his companions, unconscious and tied up. He also sees his uncle (an old man with white hair, a large bald spot, a moustache and a beard), also unconscious and tied up, and he might at this point awaked him, but I am not sure. The three monsters might have attacked the boy and his companions at this point and not before, but I am not sure. If he awoke his uncle, his uncle might have asked where he was and/or have asked what was this place, and then said his nephew’s name when he saw him, perhaps in a different order, but I am not sure (I know this sounds repetitive again, I apologize, but my memory is poor).
A group of monsters, possibly including the three monsters, surrounded the boy and his uncle, but then a group of the village’s men, with spears, attacked the monsters, and a fight ensued. His uncle might have told the boy to stop the fight, he must have done because the boy runs to the monsters and the village’s men and tells them to stop the fight and the fight stops – at least I know that the boy had something to do with the fight stopping, and the fight stops peacefully. After the fight ends, the boy and his uncle leave, and the girl says goodbye to him in front of a crowd of the village’s men who fought the monsters, the village people or children who were kidnapped by the monsters, and the monsters themselves.
He and his uncle then leave through a portal, and they fall onto subway tracks. His uncle moves them out of the way before a train comes and runs over them, or the boy moves them out of the way – they might have landed on their stomachs on the platform, but I am not sure – and the boy asks his uncle in a shocked voice, “But Uncle, I thought we were in the present!” His uncle replies “But (the name of the boy, I forgot what it is) this is the present, in another place!” or maybe he said “just in another place!” instead of “in a another place!” or “another part of the present!”, or “just another part of the present!”, or “another place in the present!”, or “just another place in the present!” Then the programme or film ended, I cannot remember if I remember the end credits.
The animation was good, and the drawing style was modern, as in it was late 90s to 2000s – it was closest to The Lost World: Dinosaur Island (which I saw in England, although I don’t know when – perhaps at the same time as I watched this television show – with the exception of the beginning and perhaps some of the middle, but I am not sure, and later saw in Canada, the entire special, on Discovery Kids) or Class of the Titans – which I know premiered a few years later in 2005 when I was in Canada, but it was the same as The Lost World: Dinosaur Island, whose drawing style was closest to what I saw – although it wasn’t identical – The Lost World: Dinosaur Island and Class of the Titans were Japanese anime-inspired, whereas what I saw was traditional Western animation.
As an end note, I say The Lost World: Dinosaur Island was where I first heard of the concept of Sir Arthur Conan Doyle’s (hey, as I was writing this a few seconds ago, I realised his name was Conan and immediately thought of Conan the Barbarian – I have seen no Conan the Barbarian films, and I never read any comics or stories about Conan the Barbarian – , I’m sorry for sounding immature, I know it’s stupid, but that’s what I thought) The Lost World, and later on, when I was older, like perhaps in 2005, I watched Sir Arthur Conan Doyle’s The Lost World on Book Television, and I liked it. And after I watched The Lost World: Dinosaur Island in Canada, I didn’t like it because they didn’t mention the book in the special, although I haven’t read the book, Sherlock Holmes for that matter, or anything else that Sir Arthur Conan Doyle might have written. So, anyways – can you tell me what this television programme or film showing on television was? I would really like to know.