0:00:03 > 0:00:04Good afternoon, you're live with Newsround,
0:00:04 > 0:00:07Ayshah here with a look at what's going on today.
0:00:07 > 0:00:11Sinking low - this sinkhole opens up in a garden in Australia.
0:00:12 > 0:00:14And flying high - thousands of mayflies take
0:00:14 > 0:00:17over a bridge in Poland.
0:00:26 > 0:00:29But first he's one of the most famous faces of Team GB.
0:00:29 > 0:00:31And with the Olympic Games just three days away
0:00:31 > 0:00:34Tom Daley has landed in Rio - a moment he's been working
0:00:34 > 0:00:37towards for eight years.
0:00:44 > 0:00:46Hi, I'm Tom Daley and over the last eight years,
0:00:46 > 0:00:49I've been working as hard as I possibly can to make my third
0:00:49 > 0:00:57Olympic dream come true.
0:00:57 > 0:01:00It started back in 2008 in Beijing, when I qualified when I was 13 years
0:01:00 > 0:01:03old and managed to compete when I was 14.
0:01:03 > 0:01:05And then in 2009, I won the World Championships.
0:01:05 > 0:01:08Ever since I got the taste of being on top of the world,
0:01:08 > 0:01:10I've always wanted to win an Olympic gold medal.
0:01:10 > 0:01:12Then in London 2012, it was the home Olympics,
0:01:12 > 0:01:14the most exciting thing ever.
0:01:14 > 0:01:15There was 18,000 people coming to support me.
0:01:15 > 0:01:17My friends, my family, millions watching at home.
0:01:17 > 0:01:19So there was a lot of pressure.
0:01:19 > 0:01:22To come away with an Olympic bronze medal was something that
0:01:22 > 0:01:23I've always dreamt of.
0:01:23 > 0:01:25And then after that into 2013, was one of my toughest
0:01:25 > 0:01:26years of diving.
0:01:26 > 0:01:28I was injured with a bad tricep.
0:01:28 > 0:01:31I was so terrified every single time I went to the diving board.
0:01:31 > 0:01:35But I managed to get through it, and I took a little bit of time out.
0:01:35 > 0:01:38I took six weeks to go and travel the world and do what I wanted
0:01:38 > 0:01:40to do, to try and reset my brain.
0:01:40 > 0:01:44Then I came back to diving, and wanted a little bit of a change.
0:01:44 > 0:01:46So I moved to London, and I had a new coach.
0:01:46 > 0:01:48And since then, I haven't really looked back.
0:01:48 > 0:01:51I've been working as hard as I possibly can.
0:01:51 > 0:01:54And then I also had to learn a new dive, which is a three
0:01:54 > 0:01:55and a half somersault with one twist.
0:01:55 > 0:01:58And that's something that was a bit of a risk, actually,
0:01:58 > 0:02:01to learn a new dive so close to the Olympic Games.
0:02:01 > 0:02:03But I feel like I'm in my peak form, peak shape.
0:02:03 > 0:02:07I just want to go out there and win an Olympic gold medal.
0:02:10 > 0:02:13Good luck, Tom.
0:02:13 > 0:02:16Toymakers have been getting into the Olympic spirit too,
0:02:16 > 0:02:17with this massive Lego model of Rio.
0:02:17 > 0:02:20More than 50 people from three different countries were involved
0:02:20 > 0:02:22in building it, they used around 953,000 pieces.
0:02:22 > 0:02:29They've created famous Rio landmarks, Olympic stadiums,
0:02:29 > 0:02:33and even athletes competing in the games.
0:02:33 > 0:02:37Now this isn't an Olympic sport, but it's just as impressive!
0:02:37 > 0:02:4013-year-old Ally set himself the challenge of going to every
0:02:40 > 0:02:42single London Underground station in just one day.
0:02:42 > 0:02:46Jenny has the story.
0:02:46 > 0:02:47Lets go!
0:02:47 > 0:02:50It's just after 10am, and Ally is on a very special
0:02:50 > 0:02:52journey with his mum and dad.
0:02:52 > 0:02:55They're trying to travel through every tube station
0:02:55 > 0:03:00on the London Underground network, all 270 of them.
0:03:00 > 0:03:02We've just been through the 67th station.
0:03:02 > 0:03:0467th station, OK.
0:03:04 > 0:03:06And next is London Bridge.
0:03:06 > 0:03:09They started in Chesham, more than 30 miles from the city
0:03:09 > 0:03:15centre, where they only had the tube driver
0:03:15 > 0:03:16for company.
0:03:16 > 0:03:17Over 7000.
0:03:17 > 0:03:18?7,000 and 84p.
0:03:18 > 0:03:19Wow.
0:03:19 > 0:03:21So we've gone up 1000 in a day.
0:03:21 > 0:03:27Very good.
0:03:27 > 0:03:30They're raising money for a cancer research charity after Ally's older
0:03:30 > 0:03:31brother died earlier this year.
0:03:31 > 0:03:33It was obviously very hard for me.
0:03:33 > 0:03:35He unfortunately passed away after all the treatment
0:03:35 > 0:03:38in March this year.
0:03:38 > 0:03:41So, I decided to make sure no one else has to go through that,
0:03:41 > 0:03:42that I would raise funds.
0:03:42 > 0:03:44Difficult, but it's quite a positive thing.
0:03:44 > 0:03:48We've had so much support from so many people.
0:03:48 > 0:03:50All through London, people we've never met,
0:03:50 > 0:03:53Transport for London.
0:03:53 > 0:03:55The charity itself.
0:03:55 > 0:03:57It's all been very feel-good in that respect.
0:03:57 > 0:04:00So yeah, it's hard, we wish we weren't having to do this.
0:04:00 > 0:04:04But it's also been a really, really positive experience as well.
0:04:04 > 0:04:08It was a lot of hard work, but Ally made it to his final stop
0:04:08 > 0:04:11and completed his challenge.
0:04:11 > 0:04:14Well done Ally.
0:04:14 > 0:04:15Staying with an underground theme - kind of.
0:04:15 > 0:04:18This sinkhole has appeared in the back garden of
0:04:18 > 0:04:19a house in Australia.
0:04:19 > 0:04:24It opened up to show swirling water and grew to eight metres wide.
0:04:24 > 0:04:26Thankfully no-one's been hurt.
0:04:26 > 0:04:31It's thought it could have been caused by an old mine shaft.
0:04:31 > 0:04:34And from sinking low to flying high - these incredible pictures show
0:04:34 > 0:04:36hundreds of thousands of mayflies taking over a bridge
0:04:36 > 0:04:39in south-eastern Poland.
0:04:39 > 0:04:42They're not harmful to humans and it's believed to show
0:04:42 > 0:04:44the environment is clean, because mayflies live
0:04:44 > 0:04:48in fresh water.
0:04:48 > 0:04:50That's it for now, Newsround is back tomorrow morning at 7:40.
0:04:50 > 0:04:53See you soon.