Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
List of caves in Bulgaria
Table title:
Partial list of Bulgarian caves
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Name </th><th colspan=1 rowspan=1 > Image </th><th colspan=1 rowspan=1 > Notes </th><th colspan=1 rowspan=1 > Length </th><th colspan=1 rowspan=1 > Location </th></tr>
<tr> <td colspan=1 rowspan=1 > Bacho Kiro </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Bacho Kiro is situated in the central Balkan Mountains, at 5 km to the west of the town Dryanovo, Gabrovo Province and at only 300 m from the Dryanovo Monastery. </td><td colspan=1 rowspan=1 > 3,500 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Devetashka </td><td colspan=1 rowspan=1 > Devetashka pestera lqto 2009 1.JPG </td><td colspan=1 rowspan=1 > Devetashka cave is situated on the east bank of the river Osam in the pre-Balkan area near the village of Devetaki, Lovech Province at around 7 km east of Letnitsa and 15 km north-east of Lovech. </td><td colspan=1 rowspan=1 > 2,442 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Devil's Throat </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > The Devil's Throat Cave is situated in the Trigrad Gorge of the western Rhodope Mountains. It is located at 1.5 km of the village of Trigrad, Smolyan Province. </td><td colspan=1 rowspan=1 > 548 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Duhlata </td><td colspan=1 rowspan=1 > Main de Tangra dans la grotte de Duhlata.JPG </td><td colspan=1 rowspan=1 > Duhlata is situated in the south-western part of the Vitosha mountain range on the left bank of the river Struma near the village of Bosnek, Pernik Province. </td><td class="highlighted"  colspan=1 rowspan=1 > 18,200 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Kolkina Dupka </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > Kolkina Dupka is situated in the western Balkan Mountains near the village of Zimevitsa, Sofia Province. As of 2018 it has a depth of -541 m, making it the deepest cave in Bulgaria; the explored galleries reach 10,300 m, placing it third in the country. </td><td colspan=1 rowspan=1 > 10,300 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Kozarnika </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Kozarnika is situated on the northern slopes of the western Balkan Mountains at 6 km from the town of Belogradchik, Vidin Province. </td><td colspan=1 rowspan=1 > 218 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Ledenika </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Ledenika is situated in the western Balkan Mountains at 16 km from the city of Vratsa, Vratsa Province. It features an abundance of galleries and impressive karst formations including stalactites and stalagmites, and is known to contain icicles. </td><td colspan=1 rowspan=1 > 320 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Magura </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Magura is situated on the northern slopes of the western Balkan Mountains near the village of Rabisha, Vidin Province. It contains prehistoric wall painting dated between 10,000 and 8,000 years ago. </td><td colspan=1 rowspan=1 > 2,608 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Orlova Chuka </td><td colspan=1 rowspan=1 > Скални форми от пещерата Орлова чука.JPG </td><td colspan=1 rowspan=1 > Orlova Chuka is situated on the left slopes of the Cherni Lom river valley. It is located at 11 km to the east of the town of Dve Mogili and 3 km to north of the village of Pepelina, Ruse Province. </td><td class="highlighted"  colspan=1 rowspan=1 > 13,437 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Prohodna </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Prohodna is situated in the pre-Balkan area in the Karlukovo Gorge of the Iskar River. It is located near the village of Karlukovo, Lovech Province. </td><td colspan=1 rowspan=1 > 262 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Raychova Dupka </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > Raychova Dupka is situated on the northern slopes of the central Balkan Mountains within Steneto Reserve in Central Balkan National Park. </td><td colspan=1 rowspan=1 > 3,333 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Razhishka </td><td colspan=1 rowspan=1 > RazhishkaCave.JPG </td><td colspan=1 rowspan=1 > Razhishka Cave is situated in the western Balkan Mountains overlooking the left bank of the Iskar River in the homonymous gorge at a height of 140 m over the river. </td><td colspan=1 rowspan=1 > 316 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Saeva dupka </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Saeva dupka is situated in the pre-Balkan area near the village of Brestnitsa, Lovech Province. It was desclared a natural landmark in 1963. </td><td colspan=1 rowspan=1 > 210 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Snezhanka </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Snezhanka is situated in the western Rhodope Mountains in the valley of Stara Reka river at some 5 km from the town of Peshtera, Pazardzhik Province. </td><td colspan=1 rowspan=1 > 368 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Temnata Dupka </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Temnata Dupka is situated in the western Balkan Mountains overlooking the left bank of the Iskar River in the homonymous gorge. </td><td colspan=1 rowspan=1 > 9,000 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Uhlovitsa </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Uhlovitsa is situated in the western Rhodope Mountains near the village of Mogilitsa, Smolyan Province. The cave features many underground waterfalls and lakes. </td><td colspan=1 rowspan=1 > 330 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Venetsa </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Venetsa is situated in the western Balkan Mountains, at 14 km to the east of the town of Belogradchik and 3 km to the south of the village of Gara Oreshets, Vidin Province. </td><td colspan=1 rowspan=1 > 220 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
<tr> <td colspan=1 rowspan=1 > Yagodinska </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > Yagodinska Cave is situated in the western Rhodope Mountains in the Buynovsko Gorge near the village of Yagodina, Smolyan Province. It is the longest cave in the Rhodope Mountains and contains a very large number of cave formations, including the rare cave pearls. </td><td colspan=1 rowspan=1 > 8,501 m </td><td colspan=1 rowspan=1 > List of caves in Bulgaria is located in Bulgaria </td></tr>
</table>
Question:
What are the longest caves in Bulgaria and what are their lengths?
Answer:
The longest caves in Bulgaria are Duhlata (18,200 m) and Orlova Chuka (13,437 m).