0:00:10 > 0:00:12Hey, everyone - Leah here with your top stories
0:00:12 > 0:00:15this Tuesday morning.
0:00:15 > 0:00:18He's one of the most famous faces of Team GB - Tom Daley.
0:00:18 > 0:00:22The star diver has landed in Rio in Brazil for the Olympics,
0:00:22 > 0:00:26which are now just three days away.
0:00:26 > 0:00:29It's a moment he's been working eight years for.
0:00:36 > 0:00:40Hi, I'm Tom Daley and over the last eight years I've been working
0:00:40 > 0:00:42as hard as I possibly can to make my third Olympic
0:00:42 > 0:00:44dream come true.
0:00:44 > 0:00:47I started back in 2008 in Beijing, when I qualified when I was 13
0:00:47 > 0:00:50years old and managed to compete when I was 14.
0:00:50 > 0:00:53Then in 2009, I won the World Championships,
0:00:53 > 0:00:56and ever since I got a taste of being on top of the world I've
0:00:56 > 0:00:58always wanted to win an Olympic gold medal.
0:00:58 > 0:01:01Then, in London 2012, it was the home Olympics
0:01:01 > 0:01:03and it was the most exciting thing ever.
0:01:03 > 0:01:05There was 18,000 people coming to support me.
0:01:05 > 0:01:08My friends, my family, millions watching at home,
0:01:08 > 0:01:12so there was a lot of pressure, and to come away with an Olympic
0:01:12 > 0:01:14bronze medal is something I've always, always dreamed of.
0:01:14 > 0:01:17To win an Olympic medal and go to the Olympics in front of a home
0:01:17 > 0:01:20crowd is something that's so hard to put into words.
0:01:20 > 0:01:23Then after that, 2013 was one of my toughest years of diving.
0:01:23 > 0:01:27I was injured with a bad tricep, my back two and a half somersaults
0:01:27 > 0:01:30with two and a half twists, which was one of the dives I had
0:01:30 > 0:01:34to redo in the Olympic final, started to go really downhill
0:01:34 > 0:01:37and I was so terrified every single time that I went to the diving pool.
0:01:37 > 0:01:41But I managed to get through it, and I took a bit of time out.
0:01:41 > 0:01:45I took six weeks to travel the world and do what I wanted to do
0:01:45 > 0:01:46to try and reset my brain.
0:01:46 > 0:01:50Then I came back to diving and wanted a little bit of a change
0:01:50 > 0:01:53so I moved to London and I had a new coach, Jane Figueiredo,
0:01:53 > 0:01:55and ever since then I haven't really looked back.
0:01:55 > 0:01:57I've been working as hard as I possibly can -
0:01:57 > 0:01:59in the weight room, with my nutrition,
0:01:59 > 0:02:00psychology, everything.
0:02:00 > 0:02:04And then I also had to learn a new dive, which is a forward three
0:02:04 > 0:02:07and a half somersaults with one twist.
0:02:07 > 0:02:11It was a bit of a risk, actually, to learn a new dive so close
0:02:11 > 0:02:13to the Olympic Games but I've been working on consistency.
0:02:13 > 0:02:16Now, going into Rio 2016, I feel like I'm in my peak
0:02:16 > 0:02:19form, peak shape.
0:02:19 > 0:02:22Hopefully, going into this competition, I just want to go out
0:02:22 > 0:02:24there and win an Olympic gold medal.
0:02:24 > 0:02:27I know it's something that seems surreal to say,
0:02:27 > 0:02:30but I have to believe that I can win that Olympic gold medal,
0:02:30 > 0:02:33and I'm going to fight to the very end with the Chinese divers.
0:02:33 > 0:02:39But, you know, wish me luck.
0:02:43 > 0:02:45Here's an unusual way to spend your summer holidays -
0:02:45 > 0:02:48one 13-year-old has been travelling to every London Underground
0:02:48 > 0:02:50station in one day.
0:02:50 > 0:02:53But there's a serious side to the challenge.
0:02:53 > 0:02:55Here's Jenny.
0:02:55 > 0:02:57Let's go!
0:02:57 > 0:02:59It's just after 10am and Ally is on a very special journey
0:02:59 > 0:03:02with his mum and dad.
0:03:02 > 0:03:04They're trying to travel through every tube station
0:03:04 > 0:03:10on the London Underground network - all 270 of them!
0:03:10 > 0:03:14We have just been through the 67th station.
0:03:14 > 0:03:16The next is London Bridge.
0:03:16 > 0:03:19The day started in Chesham, way out in zone nine,
0:03:19 > 0:03:21where they only had the tube driver for company!
0:03:21 > 0:03:23Just got a message from Gilly.
0:03:23 > 0:03:29Over ?7,000 so we have gone up a thousand in a day. Wow.
0:03:29 > 0:03:32They're raising money for a cancer research charity after Ally's older
0:03:32 > 0:03:35brother died earlier this year.
0:03:35 > 0:03:39It was obviously very hard for me.
0:03:39 > 0:03:43He unfortunately passed away after all the treatment in March
0:03:43 > 0:03:47this year, so I decided to make sure no one else has to go through that,
0:03:47 > 0:03:50that I would raise funds.
0:03:50 > 0:03:53Difficult but it's quite a positive thing.
0:03:53 > 0:04:00We've had so much support from so many people,
0:04:00 > 0:04:01all through London, people we've never met,
0:04:01 > 0:04:05people who just picked up on the story, Transport for London,
0:04:05 > 0:04:07Bloodwise, the charity itself.
0:04:07 > 0:04:09It's all really feel-good in that respect.
0:04:09 > 0:04:12So yes, it is hard, we wish we weren't having to do this,
0:04:12 > 0:04:15but it has also been a really positive experience as well.
0:04:15 > 0:04:18It was a lot of hard work but Ally made it to his final stop
0:04:18 > 0:04:21and completed the challenge.
0:04:23 > 0:04:25Take a look at these incredible pictures showing hundreds
0:04:25 > 0:04:29of thousands of mayflies taking over a bridge
0:04:29 > 0:04:32in south eastern Poland.
0:04:32 > 0:04:36Officials cleared them away using snow shovels.
0:04:36 > 0:04:38It happens just once a year and scientists
0:04:38 > 0:04:48believe their presence is proof that the environment is clean.
0:04:48 > 0:04:48That's
0:04:48 > 0:04:49That's because
0:04:49 > 0:04:49That's because mayflies
0:04:49 > 0:04:49That's because mayflies live
0:04:49 > 0:04:49That's because mayflies live in
0:04:49 > 0:04:49That's because mayflies live in fresh
0:04:49 > 0:04:51That's because mayflies live in fresh water.
0:04:51 > 0:04:52That's all from me.
0:04:52 > 0:04:54Newsround is back right here on CBBC in half an hour.
0:04:54 > 0:04:57See you then.